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.
Williams VSL, Wakeford ME. The predictive validity of the National Teacher Examinations for performance in teacher education programs. Educ Psychol Meas. 1993;53(2):533-9. doi: 10.1177/0013164493053002023