Multicenter, double-blind, comparative clinical study on the efficacy and acceptabilitty of a monthly injectable contraceptive combination of 150 mg dihydroxyprogesterone acetophenide and 10 mg estradiol enanthate compared to a monthly injectable contraceptive combination of 90 mg dihydroxyprogesterone acetophenidide and 6 mg estradiol enanthate - Coutinho, Elsimar M; Spinola, Paulo; Barbosa, Ione; Gatto, Marisa; Tomaz, Geraldez; Morais, Kléber; Yazlle, Marta Edna; Souza, Rosival Nassar de; Pinho Neto, João Sabino; Leal, Weydson de Barros; Leal, Cláudio; Hippolito, Sílvia Bomfim; et al. (Contraception, 1997)