1. HatcherRA, StewartF, TrussellJ, KowallD, GuestF, StewartGK, GatesW. Contraceptive Technology 1990–1992. 15th ed. New York: Irvington Publishers; 1990.
2. ShenfieldGM, GriffinJM. Clinical pharmacokinetics of contraceptive steroids: an update. Clin Pharmacokinet. 1991;20(1):15–37.
3. American College of Obstetricians and Gynecologists. Oral Contraceptives. ACOG Technical Bulletin no. 106. July 1987.
4. MeadeTW, GreenbergG, ThompsonSG. Progestogens and cardiovascular reactions associated with oral contraceptives and a comparison of the safety of 50- and 30-μg oestrogen preparations. BMJ. 1980;280:1157–61.
5. ThorogoodM. The epidemiology of cardiovascular disease in relation to the estrogen dose of oral contraceptives: an historical perspective. Adv Contracept. 1991;7(suppl 3):11–21.