1. New aspects of the placebo response in angina pectoris;Amsterdam;Am. J. Cardiol.,1969
2. The powerful placebo;Beecher;JAMA,1955
3. Measurement of subjective responses;Beecher,1959
4. Placebo effects: a quantitative study of suggestibility, Non-specific Factors in Drug Therapy;Beecher,1968
5. There is no convincing evidence for operant or classical conditioning in adult humans;Brewer,1974