title: Estimating the efficacy of emergency contraception.
authors.forename: Rafael T
authors.initials: RT
authors.lastname: Mikolajczyk
authors.forename: Joseph B
authors.initials: JB
authors.lastname: Stanford
mesh_terms: D003281:Contraceptives, Postcoital; D004630:Emergencies; D004717:Endometrium / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008597:Menstrual Cycle; D015588:Observer Variation; D010053:Ovary / Q000000981:diagnostic imaging*; D010060:Ovulation; D011336:Probability; D014463:Ultrasonography
chemical_list: D003281:Contraceptives, Postcoital