1. PAPANICOLAOU, G. N. At las of Exfoliative Cytology, Commonwealth Fund, Harvard University Press, Cambridge 1954 .
2. KOSS G. LEOPOLD. Diagnostic Cytology. pp. 340, 1961.
3. NATIONAL COMITTEE FOR CARERS IN MEDICAL TECHNOLOGY. Manal of Cytotechnology, 1962.
4. BERG ( J. W.) AND BADER (G. M. ): Cáncer. 11, 758 1958.
5. SONG ( Y. S. ) AND COLS. : Amer , Journ . Obst. And Gynec . 78, 1309 1959.