1. Li Y . Excessive exposure to natural fluoride and methods to reduce exposure. In Research Needs Workshop: International Collaborative Research on Fluoride. Edited by JJ Clarkson. J Dent Res 2000; 79:902.
2. International Agency for Research on Cancer. Inorganic fluorides. In International Agency for Research on Cancer Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Humans. Some Aromatic Amines, Anthraquinones and Nitroso Compounds, and Inorganic Fluorides Used in Drinking-Water and Dental Preparations. Vol. 27. Lyon: International Agency for Research on Cancer; 1982:235–303.
3. Knox EG . Fluoridation of Water and Cancer: a Review of the Epidemiological Evidence. Report of the Working Party, Department of Health and Social Security. London: Her Majesty's Stationery Office; 1985.
4. National Research Council. Health Effects of Ingested Fluoride. 7. Carcinogenicity of Fluoride. Washington DC: National Academy Press; 1993:109–123.
5. Clayson DB, Krewski D . The concept of negativity in experimental carcinogenesis. International Commission for Protection Against Environmental Mutagens and Carcinogens Working Paper No. 3. Mutation Res 1986; 167:233–240.