7Robinson JC, Plichta S, Weisman CS, etal. Dysmenorrhea and use of oral contraceptives in adolescent women attending a family planning clinic [ J ]. Am J Obstet Gynecol, 1992,166 :578.
8Hadtield R, Mardon H, Barlow D,etal. Delay in the diagnosis of endometriosis i a surcey of women from the USA and the UK[ J ]. Hum Reprod, 1996,11:878.
