1. A. Spinks, Clinical Trials, Report of a Symposium, 7seq. (The Pharmaceutical Press, London 1962).
2. Drug Amendments, USA Public Law 87, 781 (1962).
3. Code of Federal Regulations, Title 21 — Food and Drugs, subchapter C, part 130 (revised 1966).
4. S. A. Asdell, Patterns of Mammalian Reproduction, 2nd edn. (Cornell University Press, Ithaca, N.Y. 1964).
5. J. M. Morris and G. van Wagenen, Am. J. Obstet. Gynec. 96, 804 (1966).