"Alternative Medicine"
and the Psychology of Belief

James Alcock, Ph.D.

In 1988, I was part of a six-person delegation from the Committee for the Scientific Investigation of Claims of the Paranormal (CSICOP) that visited the People's Republic of China. We had been invited to investigate (a) Qi Gong, a vitalistic belief system that, among other things, is employed to diagnose and heal disease, and (b) the abilities of a group of children who, it was claimed, could read with their armpits. During our stay in Beijing, I developed a very sore throat, due, I thought, to the visibly polluted air. This made it difficult to engage in conversations and deliver the speeches that were expected of us. Eventually, I was taken to the outpatient clinic at Beijing Hospital, where, after a very brief examination, was given two medications. The first, labeled in both Chinese and English, was erythromycin, an antibiotic. That seemed reasonable enough for what I thought to be a bronchial infection. The second medication was labeled "Chuanbeiye," with the chief ingredients listed as "snake bile, tendril-leafed fritillary bulb, and almond, etc." Our interpreter assured me that she always relied on the snake bile preparation whenever she had any throat problems, but despite her earnest testimonial, I declined to use it. I relied instead upon the erythromycin, and within a few days, my throat recovered. Offered folk medicine and snake oil, I had chosen scientific Western medicine and was healed by it.

Or so I thought. After our return from China, Paul Kurtz recounted this incident in an article in CSICOP's journal, the Skeptical Inquirer. A few months later, a physician responded in letter to the editor:

All too often bronchial infections are due to viruses and therefore not treatable with antibiotics. Unfortunately, there is such a demand from the lay public to treat everything with antibiotics that it is not unusual for the encumbered physician to prescribe them for infections they know cannot be helped by antibiotics. . . . If this was a viral infection, then the antibiotic and the snake bile were of equal efficacy [1].

But I got better, didn't I? Doesn't that tell me that the antibiotic worked?

When we talk about the appeal of this treatment or that treatment, this is what is at the heart of it all—we use medicines because they seem to work. If we get better, we naturally credit the treatment (whether it had any effect or not). And when we do not improve, we naturally assume that the treatment did not work, and we may then seek out other therapies that might.

So-called alternative or complementary therapies are popular only to the extent that they can satisfy some people's needs better than conventional medical therapies do. If every visit to the family physician cured our complaints and satisfied our needs (the two are not necessarily the same), then the vast majority of people would never consider alternate therapies. And if, once people tried alternative therapies, they did not seem to be effective, most people would stop using them and they would eventually die out.

It is a mistake to assume that people who use unproven or even disproven therapies are generally less rational, less sensible, or even less educated than those who do not. Most surveys show that users of alternative medicine tend to have more years of formal education than nonusers—a by-product of the fact that these users must generally pay out of their own pockets and thus must have more disposable income [2]. No one that I have ever met would knowingly submit to treatment that he or she believed to be totally useless or harmful. We pursue a therapy because we believe—or at least hope—that it may work. (This may not apply, of course, to the radical fringe, people for whom use of alternative medicine is an integral part of an overarching sociopolitical, antiscience, or New Age worldview.)

The interesting question is how we come to believe that a therapy may be worthwhile. And since none of us is likely (even if we possess the necessary knowledge, skills, and wherewithal) to carry out clinical trials before choosing a treatment for the first time, we must ultimately base our initial decision on our faith in others' opinions and even, perhaps, others' research. However, once we decide to try a therapy, our own experience becomes very important, and a variety of psychological factors come into play that may help persuade us that the therapy is effective, even if it is not.

Most people turn to and believe in alternative therapies for the same reasons they turn to and believe in evidence-based medicine. Most users of alternative medicine are ignorant of, and uninterested in, the theoretical basis of homeopathy or chiropractic or naturopathy, just as most users of evidence-based medicine are ignorant of and uninterested in its theoretical underpinnings. Physicians have taught us not to enquire too much about what is in this tablet or how that injection works. We wouldn't be able to understand it anyway, and after all, we have come to the physician because we trust that he or she understands so that we don't have to. Most people who keep using alternative therapies do so because they believe it helps, just as is the case with those who continue to go back for treatment with evidence-based therapies.

In the end, it boils down to what our individual belief systems incline us to accept as evidence. This article discusses how we learn about causality, how our beliefs and our trust develop, and how this shapes our concepts of illness and healing. It is through these mechanisms that people come to have confidence in any therapy, evidence-based or not, and effective or not.

How We Learn About Causality

When I stated earlier that the antibiotic made me better, what did that statement actually mean? In reality, all that happened was that two events occurred in succession: One, I took the medicine, and two, not too long afterwards, I felt better. Yet, my conclusion was a causal one: The medicine made me better. That is consistent with my limited knowledge of medicine and my expectations. Since I knew nothing directly about the causal link, or even for sure if there was one, my judgement was really magical thinking. Magical thinking describes what happens when we experience two successive events and conclude that the first event caused the second, without any concern for the putative causal link. All humans are to some degree magical thinkers. Until recently, most psychologists used to think that textbook logic and reasoning practices were the "default mode," and that when people engaged in magical or superstitious thinking it was some kind of pathology, a deviation from the inbred norm. Research has taught us, however, that magical thinking (i.e., "quick-and-dirty" reasoning tactics that get it more or less right a sufficient portion of the time to be useful) is our first line of attack when reckoning with the world—logical, analytical reasoning is a fragile add-on that must be painstakingly learned [3-5].

We actually have two quite distinct information-processing systems in our brains and nervous systems that lead us to conclusions about causality. On the one hand, we learn quickly from direct experience. Put your finger in a live lamp socket, and your experience quickly teaches you not to do that again. This is experiential learning. No knowledge of electricity, no understanding of physics, is necessary. A dumb animal would learn as quickly not to touch the socket again. On the other hand, we also process information in an intellectual manner, through reasoning, logic, and analysis. Through intellectual learning, we come to know that a flow of electrons races down our finger when we touch a live contact point in the socket, and we can learn to avoid touching sockets even if we have never had any direct experience with them.

Experiential Learning

Experiential learning occurs at a primitive level—it is automatic, rapid, and often tied up with emotional reactions. It requires no formal teaching, no practice, no theoretical understanding, no contemplation, no logic. It is based on patterns that we detect in the world around us.

We enter this world superbly equipped to learn quickly about our environment. Our nervous systems are bombarded with an unending shower of sensory stimulation from both within and without our bodies. We are able at birth to begin to find patterns in this stimulation, to make sense out of it. To do so we rely on two factors—temporal contiguity and stimulus generalization. By temporal contiguity, I mean that events that occur closely together in time have a special impact on our nervous systems; they set up an "association" in our brains. Touch a hot stove, feel pain, and the nervous system "learns" to avoid the hot stove. And then, by the process of stimulus generalization, one learns not only to avoid that stove, the one that caused the pain, but other stoves and any object that looks similar to that stove. In other words, without the need for any reasoning or logic or words or understanding, we quickly internalize some "knowledge" about the world—don't touch stoves; they cause pain. The importance of such learning for survival is obvious. Yet, again, note the imputation of causality, when all we really experience is temporal contiguity. This applies just as readily to positive outcomes: Take a pill and the headache goes away. We attribute the pain relief to the pill.

Asymmetric effect of pairing and nonpairing. It is important to understand, as I have discussed in detail elsewhere [6,7], that we do not easily unlearn associations between important events. If the infant, by accident, touches the same stove a day later, but this time it is cold and so no pain occurs, his or her nervous system does not simply reset to itself to zero so far as stoves are concerned. Obviously, this would not be very adaptive in terms of our survival: The rabbit that encounters a snarling, biting fox and lives to remember it would not be well served by a nervous system that unlearns the fear of foxes, just because on one occasion, the rabbit encounters a fox that makes no effort to turn it into dinner. The association set up by the co-occurrence of two significant events is not easily undone. If your migraine went away last week when you took a pill, but did not abate when you took another pill today, would you decide that the pill does not work after all? Not likely.

Intermittent reinforcement. Indeed, what happens if, ten times in a row, the child accidentally brushes against the stove, but the stove is cool? With an accumulation of such experiences, the association between stove and pain will gradually weaken, but—and this is a very important "but"—if every now and then touching the stove produces pain, this results in an even more enduring association between stove and pain, for one automatically learns that the fact that the stove was harmless enough—even a number of times in a row—does not mean that it will not burn the next time. Occasional, intermittent reinforcement produces even more enduring associations than continuous reinforcement -- if you doubt this fact, just watch the "one-armed bandit" players in any casino for a while. The intermittent reinforcement effect is just as true for the pill that is followed by relief every now and then, if there is no other apparent relief mechanism available.

Superstitious conditioning. I have been discussing a situation where there actually is a causal relationship between the hot stove and pain and perhaps between pill and relief. However, our nervous systems have no direct way of knowing that. That conclusion belongs to the realm of reason, not experience. Suppose that by happenstance, a child reaches for a new toy just as there is a terrible clap of thunder that frightens him or her. The association will be set up between toy and the fearful noise, and the child may from now on avoid that toy. This is referred to as superstitious conditioning. It is interesting to note that the term "superstitious" is applied by the observer who knows that there really is not a causal link. In fact, most of the time, when we are inferring causality, we cannot really tell whether there is a causal link or not. We take the vitamin C and feel better, or we don't catch a cold; did one cause the other? We are likely to think so -- especially if we have other reasons—authority, testimonials, and beliefs consistent with that interpretation. Only very careful and time-consuming research can really tell us whether there is any causality involved at all.

Intellectual Learning

Be that as it may, while our experiential learning is of vital importance for survival, the major reason that we have triumphed over other species and made them part of our food chain, rather than the other way around, is that we possess relatively advanced cognitive abilities. With our rich heritage of logical analysis and our culturally-codified knowledge base, we are able, through contemplation, to estimate the value and meaning of most things around us. And through our highly efficacious communication abilities, we can teach our children about "how things work," without the need for them to go out and experience everything firsthand, or to develop intellectual understanding from basic principles. (Now, if we could only get them to pay attention!)

Yet, we have to learn how to learn in this way. We have to learn logic. We have to learn how to organize our knowledge into categories and categories into an explanatory framework. We have to learn that surface appearances don't always relate to underlying realities. And just as it took civilization thousands of years to develop what we think of today as logic and scientific inquiry, so each individual spends many years in formal education. In this way, each of us is taught how to think in a logical manner, although, strangely enough, not all that much of children's formal education is devoted to developing logical abilities that will serve them well in everyday life. There is no reason why we could not teach children in grade 5 about the need for double-blind randomized clinical trials, especially if we used age-appropriate, attention-grabbing examples. They could understand, and it would be a big step towards fostering critical thinkers, savvy consumers, and informed voters.

Human beings are constantly seeking to "understand." We want explanations for events around us. What was that noise in the garage? There should be no one in there—is it a raccoon, a burglar, the wind, or am I just "hearing things"? Why isn't my doctor curing my condition? We make causal attributions continually—the floor is wet because the shower curtain was not all the way into the bathtub. The tree branch was blown down by the wind. Martha ignored me because she is envious. Harry was nice to me because he wants to borrow some money. I got better because I took the erythromycin. And most of us are uncomfortable when we are unable to assign causes to events. "Harry is floating in midair. Shucks, that is strange; but I don't have an explanation, so I will just forget about it." Martha recovered from terminal cancer, when the doctors said she would die—it must have been the laetrile that saved her, or it must have been the prayer. Most of us, in our personal lives, have a hard time accepting ambiguity, accepting that sometimes we just don't know.

Conflicts between the Experiential and the Intellectual

As determined as we may be to base our decisions on fact, not faith; intellect, not emotion; reason, not rhetoric; we can do so only up to a point. Like it or not, our lives are to a considerable degree governed by primitive associations hardened into our nervous systems by experience.

There will be times where we "know" one thing intellectually, but "feel" strongly something else. You may "know" that the garter snake in the cage cannot really hurt you, but you cannot push yourself to touch it. You may "know" that flying through turbulence is not dangerous and no different than being on a motor boat on some choppy water, but nonetheless, you may feel irrational, even incapacitating, fear.

What do we do when faced with the choice between going with logic or emotion, reason or intuition? As much as we may be dedicated to reason, emotion has a very forceful way of making us an offer that is hard to refuse. As the public speaker seized by stage fright knows all too well, we cannot by virtue of rationality or willpower simply turn off those powerful feelings—and they are often impossible to ignore. Sometimes, the easiest way to reduce the conflict is to bring the intellect into line with the emotions, because most often we cannot do the opposite [8]. "Yes, airplanes are dangerous—my fear is justified." And if evidence-based medicine can't cure you, and alternative medicine says it can, which do you believe? Many people experience a decrease in anxiety if they accept the alternative healer's claims, and that anxiety relief may thwart whatever challenges are mounted by data and intellect.

Beliefs

Our beliefs are, in essence, our expectations about the world around us. I believe the road continues on the other side of the hill. I believe that submitting to surgery will take away the pain in my belly, even it the pain initially increases. I believe that oil of tangerine will cure my headaches. But where do our beliefs originate?

Authority is, of course, a primary source of belief. We spend many years in school, being pushed to master sets of facts provided by authority, most of which we have very limited means to challenge. Similarly, the media bombard us with assertions that many are inclined to accept because, "They couldn't say that on TV if it weren't true, could they?" And our most unshakeable beliefs are often those for which we have no direct experiential support, but have come down to us from one authority or another, and are shared by people around us. For example, we learn that the earth is not flat—despite whatever our direct experience of it might suggest, and even though it is the rare person indeed who has ever actually tried to conduct research into the claim. Most would not even know where to begin. But we do not hear many people expressing doubt on the matter. We all accepted what was, initially at least, handed down by authority. And if someone in authority, even if that authority is self-proclaimed, tells me to reduce the amount of fat in my diet in order to preserve my health, or tells me to take St. John's Wort if I am depressed, why shouldn't I believe?

Our beliefs become integrated into a fabric that makes them difficult to change, even if information that contradicts them comes along [9]. If I come to believe that chiropractic is effective therapy, then even if research studies find no benefit, "it must work—it helped my back, my uncle swears by it, health insurance covers it, a regulatory body supervises it. One study isn't going to convince me that all those people are wrong." This is as true for our personal beliefs about aspirin or penicillin as it is for chiropractic or Echinacea.

Of course, the social support resulting from a sharing of belief is important. If you have never heard of oil of tangerine until I mention it, you may hesitate to take it, but if you have read testimonials about its virtues; if you have other acquaintances who use it, it is more likely that you will try it, and you will want it to work. You may reason, "What's the harm—if it doesn't work, at least it can't hurt me"—or so many people are predisposed to believe about alternative therapies.

Of course, we do learn to be skeptical, too. We soon learn that not all sources of information are equally reliable, and as we become better educated by life, we come to accept information from some sources almost without question, while routinely discrediting information from other sources. But how do we choose our sources, our authorities? I allow certain people wearing white coats to inject substances into my veins, almost at their whim, or to put their fingers in orifices that they were not designed to enter, without being told anything other than the potion or the prodding will have a therapeutic or diagnostic benefit. Yet, certain other people in white coats who may want to give my neck a good twist or insert tiny needles into my skin with the promise of bringing benefit I do not allow near me. Why not? We all have learned to choose our authorities.

Illness and Healing

Now let's turn to a series of questions about illness and healing:

How Do We Know We Are Ill?

Language is a wonderful tool for disseminating knowledge about most things in our world. However, since we have no method of determining whether or not a child is in pain, or whether or not a child is frightened or worried, except by judging his or her behavior, how do we know what a child is feeling? Of course, we do not, not before the child can talk. We may measure the child's temperature and decide that there is fever, but is the inference that the child feels in pain or sickly necessarily correct? We don't know.

We teach young children about their emotional states, about pain, about sickness, by our judgments of what they must be feeling or should be feeling. We teach them the language of pain and illness: "I feel like I am going to die" or, "It's nothing, just a flesh wound." We teach children to relax or to worry, based on our reactions to our definition of what is going on inside them. We teach children—and this is in part culturally based of course, a sick role—how they are to react—to be passive, dependent, let the parent or doctor take care of them [10]. And since, even as we grow up, the innards of our bodies remain to a very large extent unknown to us, we teach children to rely for the most part on other people—on authorities—to tell them what is wrong and to fix the problem. We learn that when we are sick, our job as patient is to follow orders and the doctor's job is to make us better.

But I come back to the question of how we know we are sick. Generally, it is simply because we don't feel well, or we are vomiting, or we are always tired, or we experience pain, dizziness, or difficulty moving. None of these necessarily means that we are have a disease, but we are likely to view them as problems that need treatment. Indeed, some people grow up learning to interpret many aspects of emotional distress as having a physical rather than an emotional basis [11]. And so we go to the physician or homeopath or chiropractor.

How Do We Choose a Therapist or Therapy?

The choice of therapy brings us back to the subject of authority again. For most people, credentials are very important. But what are credentials? A Doctor of Medicine has credentials. A Doctor of Chiropractic has credentials, as does a Doctor of Naturopathy or a Doctor of Traditional Chinese Medicine. How is the public to choose among them? A Doctor is a Doctor is a Doctor to most people. When pharmacies promote herbal remedies alongside pharmaceuticals, when the nursing profession does not speak out against laying on of hands ("therapeutic touch"), and supposedly responsible media programs tout the benefits of unproven therapies, how is the public to choose among the various credentialed authorities? Not even looking for a basis in science is enough: Just as during wartime, when each nation proclaims that "God is on our side," so too do most promoters of therapy—whether conventional or alternative—claim science as their ally. Homeopathy, we are told, has passed scientific muster. Chiropractic is described as an art and a science and a philosophy. Say, which is that "scientific" medicine again?

Moreover, we happen to live in an age where there is, in many quarters, a growing distrust of established authorities. Today's distrust of authority is based in part on a devolution of social power that brings more and more decision making to the level of the individual, leaving less and less control in the hands of politicians, priests, physicians, and professors. On the whole, this is probably a positive development. However, when people are encouraged to make choices about health care, but are missing the tools they need to weigh one therapy against another, they are not necessarily better off, and may sometimes be much worse off, than when designated authorities made such decisions for them.

What if the Therapist Says There Is Nothing Wrong?

What if the family physician informs you that the vomiting is due to stress and you should change careers, or tells you that your pain is just something that you will have to live with? Doctors are supposed to make us well. There is nothing in television advertising that says "Live with your headaches" or "There is not a pill for everything." If the doctor isn't making us well, then maybe we need another doctor. And if that doctor fails, then maybe we need another kind of therapy—at least one where they promise relief.

How Do We Know That a Therapy Works?

When we are given therapy for our problem, how do we know it works? I come back to where I started out, with the antibiotic. It works—we surmise—if we feel better. It works if our sore throat goes away or our backache improves or our warts disappear.

There are many reasons why we might feel improvement, however, even if the therapy has absolutely no effect. We may feel better after the treatment, even if it really had no effect, because:

These and other factors [12], can lead us to perceive improvement in our symptoms as being caused by the treatment, thereby validating both therapy and therapist, and setting into play a new round of testimonials.

Incidentally, if "feeling better" is one criterion for judging a therapy as effective, what happens if we did not feel bad in the first place? Consider this: Research indicates that at least one-third of all patients do not comply with the medical regime suggested by their physicians [13]. Noncompliance is a particular problem when patients do not know they have a problem until they undergo a routine checkup. For example, even though hypertension can lead to stoke, heart failure, renal failure, and blindness, between 75 and 90 percent of patients diagnosed with this disorder fail to take their medication regularly or follow other recommendations[14]. Why such noncompliance? In part, it may be because the symptoms of hypertension are not usually obvious to the patient, who may wish to minimize the perceived threat by persuading him- or herself that there really is not a problem. This is a kind of "alternative nonmedicine" -- if you feel all right, don't take anything!

However, there is more to it than that. The research literature shows that patients comply more when they regard their physician as caring, friendly, and interested in them[15]. Patients are also more likely to comply when physicians make definite follow-up appointments in order to monitor progress [16]. This again points to an advantage that some alternative therapists have over conventional physicians—increased specialization and technology and the economics of managed, third-party-payer health care tends to produce a rationing of the leisurely "bedside manner" that many patients crave almost as much as effective therapy itself. Alternative healers can cater to this need for reassurance, existential support, and sympathetic human interaction by being more friendly, chatty, taking more time, and scheduling a series of "maintenance" or "wellness" appointments. This in itself is not necessarily a bad thing, unless the alternative healer offers something dangerous, extracts unconscionable sums of money, or diverts the patient from proven therapies.

Alternative Medicine vs Scientific Medicine

So, when we ask "What makes people think that alternative remedies work?" we should first ask ourselves "What makes people think that conventional medicine works?" The answer to the two questions is pretty much the same. We think they work largely "because" we feel better after taking them, or authorities tell us that we are better. Post hoc ergo propter hoc, after the fact, therefore because of the fact. (Note that I am discussing the reasons for belief in a therapy, and not the efficacy of the therapy, per se). Proponents of alternative therapies are largely winning the public relations war with their hopeful, uplifting messages, whereas proponents of scientific biomedicine have so often assumed that the superiority of their product was self-evident (while underestimating the strength of the "antidoctor backlash" in society).

Alternative remedies have appeal to the extent that conventional remedies fail to provide relief. Indeed, the areas where alternative therapies seem to have most appeal is in the very areas where conventional therapies are not able to satisfy the expectations of the consumer, e.g., chronic headaches and backaches, low energy, nausea, arthritis, gastrointestinal complaints, allergies, things which are often caused by or exacerbated by stress or emotional disorders. The alternative therapist, through validating the client's complaints (and often his or her unconventional worldview), providing hope for overcoming the complaints, and giving much personal attention and support, can indirectly serve some of the emotional needs that often underlie many complaints that physicians dismiss. They also offer hope for conditions that physicians cannot cure.

Remember Chuanbeiye, the snake bile preparation I mentioned at the beginning? On the back of the box is written the following:

This is an efficacious drug for sputum crudum, cough, asthma caused by cold, bronchitis and bronchitis chronic, etc. Because it is very sweet and convenient for taking therefore it is very welcomed by diseases at home and abroad. The effective rate that treats these diseases is 96.8% and the apparent effective rate is more than 76.8%.

That seems to suggest that some people get better but don't realize it! Whatever the author really meant to say, as patients with a disease, we have to leave it to medical scientists to establish the real effective rate. All our experience tells us about is the apparent effective rate, how often we seem to improve when we take the medicine, whether it actually helps or not. For the reasons I have discussed in this paper, it should not be surprising that alternative medicine is capable of producing "apparent effective rates" that are even higher in some circumstances than those produced by evidence-based medicine. Ultimately, therein lies their appeal.

References

  1. Cloutier RP. Infection irony. The Skeptical Inquirer 13:331, 1989.
  2. Beyerstein BL. Alternative medicine. Where's the evidence? Canadian Journal of Public Health 88:149-150, 1997.
  3. Gilovich T. How We Know What Isn't So: The Fallibility of Human Reason in Everyday Life. New York, NY: Free Press/Macmillan, 1991.
  4. Schick T, Vaughn L. How to Think about Weird Things: Critical Thinking for a New Age. Mountain View, CA: Mayfield Publishing,1995.
  5. Levy D. Tools of Critical Thinking. Boston, MA: Allyn and Bacon, 1997.
  6. Alcock JE. Parapsychology: Science or Magic? Oxford, UK: Pergamon, 1981.
  7. Alcock JE. The belief engine. Skeptical Inquirer 19(3):14-18, 1995.
  8. Festinger L. A Theory of Cognitive Dissonance. Stanford, CA: Stanford University Press, 1957.
  9. Alcock JE, Carment DW, Sadava SW. Attitude change. A Textbook of Social Psychology. 4th edition. Scarborough, Ontario: Prentice-Hall Canada; 1998.
  10. Alcock JE. Chronic pain and the injured worker. Canadian Psychology 27:196-203, 1986.
  11. Shorter E. From Paralysis to Fatigue: A History of Psychosomatic Illness in the Modern Era. New York, NY: Free Press, 1992.
  12. Stone GC. Patient compliance and the role of the expert. Journal of Social Issues 35:34-59, 1979.
  13. Beyerstein B.
  14. Leventhal H, Hirschman RS. Social psychology and prevention. In: Sanders GS, Suls J, eds. Social Psychology of Health and Illness. Hillsdale, NJ: Erlbaum, 1982: 387-401.
  15. DiNicola DD, DiMatteo MR. Practitioners, patients, and compliance with medical regimes: a social psychological perspective. In: Baum A, Taylor SE, Singer JE, editors. Handbook of Psychology and Health. Vol 4. Hillsdale, NJ: Erlbaum, 1984: 5-64.
  16. DiMatteo MR, Sherbourne CD, Hays RD, and others. Physicians' characteristics influencing patients' adherence to medical treatment: Results from the medical outcomes study. Health Psychology 12:93-102, 1993.

Dr. Alcock is professor of psychology at York University in Toronto, Canada.

This article was posted on June 25, 2001.

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