1. Examination of sputum from a case of cancer of the pharynx and adjacent parts;Beale;Arch. Med. (London),1861
2. Value of cytologic techniques in screening lung cancer;Boucot,1951
3. Value of cytologic techniques in screening uterine and lung cancer;Day,1951
4. 1853, cited at Am. Cancer Soc. Symposium on Exfoliative Cytology;Donaldson,1951
5. 1800's, cited by Scheffey, L.C., at Am. Cancer Soc. Symposium on Exfoliative Cytology;Drysdale,1951