1. Variation of the human menstrual cycle through reproductive life;Treloar;Int J Fertil,1967
2. The degree of variability of the length of the menstrual cycle in correlation with age of woman;Vollman;Gynaecologia,1956
3. The length and variability of the human menstrual cycle;Chiazze;JAMA,1968
4. Statistical studies on menstruation; a criticism on the definition of normal menstruation;Matsumoto;Gunma J Med Sci,1962
5. Probability of menopause with increasing duration of amenorrhea in middle-aged women;Wallace;Am J Obstet Gynecol,1979