Johannes CB, Crawford SL, Longcope C, McKinley SM. Bleeding patterns and changes in the perimenopause: a longitudinal characterization of menstrual cycles. Clin Consultations Obstetr Gynecol. 1996;8:9-20.
Clarkson T, Anthony MS, Hughes C. Estrogenic soybean isoflavones and chronic disease: risks and benefits. Trends Endocrinol Metab. 1995 Jan;6(1):11-6.