1. V. L. Granovskii and E. I. Urazakov, Zh. Eksp. Teor. Fiz. 38, 1354 (1960) [Sov. Phys. JETP 11, 974 (1960)].
2. E. I. Urazakov, Zh. Eksp. Teor. Fiz. 44, 41 (1963) [Sov. Phys. JETP 17, 28 (1963)].
3. V. M. Zakharova, Yu. M. Kagan, and V. I. Perel’, Opt. Spektrosk. 11, 777 (1961).
4. V. M. Zakharova and Yu. M. Kagan, Opt. Spektrosk. 19, 140 (1965).
5. V. Yu. Karasev, R. I. Semenov, and M. P. Chaika, in Proceedings of the All-Russia Conference on the Physics of Low-Temperature Plasma (FNTP-98), Petrozavodsk, Russia, June 22–27, 1998, Ed. by A. D. Khakhaev (Petrozavodsk University, Petrozavodsk, 1998), p. 268.