1. Achievements in public health, 1900–1999: family planning;Centers for Disease Control;MMWR Morb Mortal Wkly Rep,1999
2. World Contraceptive Patterns;United Nations Population Division,2013
3. Ovarian activity during regular oral contraceptive use;Crosignani;Contraception,1996
4. Classification and pharmacology of progestins;Schindler;Maturitas,2008
5. Long-term experience with Enovid among clinic patients: results after 2 1/2 to 6 years of individual patient use;Sturtevant;J Reprod Med,1970