1. H. Massey and E. Burhop, Electronic and Ionic Impact Phenomena, Oxford University Press (1971).
2. I. P. Bogdanova and V. D. Marusin, Opt. Spectrosk.,27, 719 (1969).
3. A. I. Korotkov and N. A. Prilezhaeva, Izv. Vyssh. Uchebn. Zaved., Fiz., No. 12, 85 (1970).
4. A. I. Korotkov, Yu. S. Gur'ev, and S. M. Kazakov, Opt. Spectrosk.,39, 1028 (1975).
5. G. J. Schulz and R. E. Fox, Phys. Rev.,106, 1179 (1957).