[THE CONTRACEPTIVE RING AND EXTRAUTERINE PREGNANCY].
D003270:Contraceptive Agents; D003273:Contraceptive Devices; D005260:Female; D006801:Humans; D011247:Pregnancy; D011271:Pregnancy, Ectopic
D003270:Contraceptive Agents
CONTRACEPTIVE DEVICES; PREGNANCY; PREGNANCY, ECTOPIC