1. M. Blohmke, Institute of Medicine of Labor, University of Heidelberg, personal communication, 1977.
2. See for instance: I. B. Weinstein, H. Yamasaki, M. Wigler, L.-S. Lee, P. B. Fisher, A. Jeffrey, and D. Grünberger, in “Carcinogens: Identification and Mechanisms of Action”, (eds. C. Griffin and C. P. Show) Raven Press, New York, 1979, p. 399
3. I. B. Weinstein, J. Arcolo, M. Lambert, W. Hsiao, S. Gattoni-Celli, A. M. Jeffrey, and P. Kirschmeier, in “Molecular Biology of Tumor Cells”, (eds. B. Wahren et al.) Raven Press, New York, 1985, p. 55.
4. I. B. Weinstein, personal communication, 1986.
5. A. v. Metzler, Z. Krebsforschung 83, 195 (1975) (in German).