1. Comparison of three single doses of mifepristone as emergency contraception;Lancet,1999
2. Low doses of mifepristone for emergency contraception;Cheng;Chin J Obstet Gynecol,1999
3. The post-coital copper-T;Lippes;Adv Plann Parent,1976
4. Postcoital intrauterine device insertion —a further evaluation;Black;Contraception,1980
5. Emergency contraception;Haspels;Contraception,1994