Randomized clinical trial of a levonorgestrel-releasing intrauterine system and a depot GnRH analogue for the treatment of chronic pelvic pain in women with endometriosis - Petta, Carlos A.; Ferriani, Rui Alberto; Abrão, Maurício Simões; Hassan, Daniela; Rosa e Silva, Júlio César; Podgaec, Sérgio; Bahamondes, Luis (Human Reproduction, 2005)