1. Benedict, W. F., Rucker, N., Faust, J., Kouri, R. E.: Malignant transformation of mouse cells by cigarette smoke condensate. Cancer Res. 35, 857?860 (1975)
2. Doll, R., Peto, R.: Mortality in relation to smoking: 20 years' observations on male British doctors. Br. Med. J. 1976 II, 1525?1536
3. Freeman, A. E., Kelloff, G. J., Gilden, R. V., Lane, W. T., Swain, A. P., Huebner, R. J.: Activation and isolation of hamster-specific C-type viruses from tumors induced by cell cultures transformed by chemical carcinogens. Proc. Natl. Acad. Sci. USA 68, 2386?2390 (1971)
4. Gori, G. B.: Low-risk cigarettes: A prescription. Science 194, 1243?1246 (1976)
5. Groenen, P. J., Ten Noever de Brauw, M. C.: Determination of volatile N-nitrosamines in the vapour phase of the smoke from various tobacco products. Beitr. Tabakforsch. 8, 113?123 (1975)