1. AMERICAN CANCER SOCIETY (1974). Facts and Figures. New York.
2. Possible microbial contribution to nitrosamine formation in sewage and soil;AYANABA;J. Natl. Cancer Inst.,1973
3. The geographic pathology of bowel cancer;BERG;Cancer,1974
4. Esophageal cancer in the Bantu of the Transkei associated with mineral deficiency in garden plants;BURRELL;J. Natl. Cancer. Inst.,1966
5. On the epidemiology of nasopharyngeal carcinoma;CLIFFORD;Internat. J. Cancer,1970