1. Trends in contraceptive practice 1965–1973;Westoff;Fam Plann Perspect,1976
2. Prevalence and trends in oral contraceptive use in pre-menopausal females ages 15-54 years, United States, 1971-1980;Russell-Briefel;Am J Publ Health,1985
3. The Gallup Organization, Inc. Attitudes toward contraception. Conducted for The American College of Obstetricians and Gynecologists. March 1, 1985, Princeton, New Jersey.
4. Clinical epidemiology;Fletcher,1988
5. Epidemiologic assessment of the risks of oral contraception;Petitti;J Reprod Med,1986