1. Cf for example: Kulkarni, P. N., Blair, A. H., Ghose, T. I.: Cancer Res. 41, 2700 (1981)
2. Cf for example: Porter, C. W., Bergeron, R. J., Stolowich, N. J.: ibid. 42, 4072 (1982)
3. Labarre, J.-F.: Topics in Current Chemistry 102, 1 (1982)
4. Cernov, V. A., Litkina, V. B., Sergievskaya, S. I., Kropacheva, A. A., Pershina, V. A., Sventsitkaya, L. E.: Farmakol. Toksikol. (Moscow) 22, 365 (1959)
5. Labarre, J.-F., Cros, S., Faucher, J.-P., Francois, G., Levy, G., Paoletti, C., Sournies, F.: 2nd Int. Symp. Inorganic Ring Systems (IRIS), Göttingen, Gesellschaft Deutscher Chemiker, Proceedings p. 44 (1978)