Francisco Alvarez

Prolonged intrauterine contraception: A seven-year randomized study of the levonorgestrel 20 mcg/day (LNg 20) and the Copper T380 Ag IUDS

Irving Sivin, Janet Stern, Elsimar Metzker Coutinho et al. · Contraception · 1991 · 237 citations · Full text

Medicine, Gynecology, Obstetrics +14

Long-term contraception with the levonorgestrel 20 mcg/day (LNg 20) and the Copper T 380Ag intrauterine devices: A five-year randomized study

Irving Sivin, Sayed El Mahgoub, Terence McCarthy et al. · Contraception · 1990 · 180 citations

Medicine, Gynecology, Obstetrics +13

Anovulation, inadequate luteal phase and poor sperm penetration in cervical mucus during prolonged use of NORPLANTR implants

Vivian Brache, Aníbal Faúndes, Elof D.B. Johansson et al. · Contraception · 1985 · 119 citations

Medicine, Gynecology, Obstetrics +17

A Clinical Trial of 7α-Methyl-19-Nortestosterone Implants for Possible Use as a Long-Acting Contraceptive for Men

Sigrid von Eckardstein, Gabriela Noé, Vivian Brache et al. · The Journal of Clinical Endocrinology & Metabolism · 2003 · 114 citations · Full text

Medicine, Endocrinology, Pharmacotherapy +17

Contraceptives for lactating women: A comparative trial of a progesterone-releasing vaginal ring and the Copper T 380A IUD

Irving Sivin, Horacio B. Croxatto, Patricia Y. Miranda et al. · Contraception · 1997 · 81 citations

Medicine, Gynecology, Obstetrics +15