1. Pouchet FA: Theorie positive de l’ovulation spontanée et de la fécondation des mammifères et de l’espèce humaine, basée sur l’observation de tante la serie animale. Paris, Bailliere, 1847
2. Stockard CR, Papanicolaou GN: A rhythmical “heat period” in the guinea pig. Science 46: 1176–1182, 1917
3. Papanicolaou GN: The sexual cycle in the human female as revealed by vaginal smears. Am J Anat 52 (suppl): 519–637, 1933
4. Papanicolaou GN: Existence of a “post-menopause” sexual rhythm in women, as indicated by the study of vaginal smears. Anat Rec 55 (suppl): 71–72, 1933
5. Frankel L, Papanicolaou GN: Growth, desquamation and involution of the vaginal epithelium of fetuses and children with consideration of the related hormonal factors. Am J Anat 62: 427–441, 1938