New frontiers of contraception.
D003267:Contraception; D003271:Contraceptive Agents, Female / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007435:Intrauterine Devices, Copper; D009640:Norethindrone / Q000494:pharmacology; D012106:Research
D003271:Contraceptive Agents, Female; D009640:Norethindrone