Two years of intrauterine contraception with levonorgestrel and with copper: A randomized comparison of the TCu 380Ag and levonorgestrel 20 mcg/day deviceContraception - Tập 35 - Trang 245-255 - 1987
Irving Sivin, Janet Stern, Juan Diaz, M.Margarita Diaz, Anibal Faundes, Sayed El Mahgoub, Soledad Diaz, Margarita Pavez, Elsimar Coutinho, Carlos E.R. Mattos, Terry McCarthy, D.R. Mishell, Donna Shoupe, Francisco Alvarez, Vivian Brache, Elvira Jimenez