title: Combined oral contraceptives versus levonorgestrel for emergency contraception.
authors.affiliation: Saint Louis University Family Practice Residency, Belleville, Illinois, USA. sstrayer@apci.net
authors.forename: S M
authors.initials: SM
authors.lastname: Strayer
authors.forename: R L
authors.initials: RL
authors.lastname: Couchenour
mesh_terms: D003277:Contraceptives, Oral, Combined; D003280:Contraceptives, Oral, Synthetic; D003281:Contraceptives, Postcoital; D004630:Emergencies; D005260:Female; D006801:Humans; D016912:Levonorgestrel; D011247:Pregnancy / Q000706:statistics & numerical data; D012107:Research Design
chemical_list: D003277:Contraceptives, Oral, Combined; D003280:Contraceptives, Oral, Synthetic; D003281:Contraceptives, Postcoital; D016912:Levonorgestrel