1. V. M. Zelichenko and E. V. Koryukina, Izv. Vyssh. Uchebn. Zaved., Fiz., No. 7, 8?14 (1988).
2. V. M. Zelichenko and E. V. Koryukina, Proceedings of the 20th All-Union Conference on Spectroscopy, Kiev (1988), p. 57.
3. Wu Mu Shiang, J. Phys. B,18, No. 10, L271-L273 (1985).
4. J. Hendekovic, Chem. Phys. Lett.,90, No. 3, 198?201 (1982).
5. V. M. Zelichenko and E. V. Koryukina, Letter to the Editor, Izv. Vyssh. Uchebn. Zaved., Fiz., Tomsk (1990), p. 25, on deposit in VINITI 12.21.90, No. 6377.