1. World Medical Association. 52nd Revision of the Declaration of Helsinki. General Assembly. Edinburgh, Scotland; October 2000.
2. World Medical Association. Newsletter, October 2001. Declaration of Helsinki: Note of Clarification on placebo-controlled trials. Available at: www.wma.net/e/home.html. (Accessed October 16, 2001).
3. US Code of Federal Regulations. Food and Drug Administration; 21 CFR Parts 50 and 56.
4. US Code of Federal Regulation. National Institutes of Health; 45 CFR Part 46.
5. Baruch AB. When are placebo-controlled trials no longer appropriate? Control Clin Trials. 1997;18:602–612.