Endocrine features of menstrual cycles in middle and late reproductive age and the menopausal transition classified according to the Staging of Reproductive Aging Workshop (STRAW) staging system - Hale,G.E.; Zhao,X.; Hughes,C.L.; Burger,H.G.; Robertson,D.M.; Fraser,I.S. (J Clin Endocrinol Metab, 2007)