1. C. Hartung and R. Jurgeit, Appl. Phys. B, B27, 39–41 (1982).
2. A. Gerasimchuk, S. Kornilov, I. Ostrejkovskij, E. Protsenko, and S. Tymper, Appl. Phys. B., B55, 503–508 (1992).
3. S. T. Kornilov, V. M. Prokopova, E. D. Protsenko, and S. I. Tymper, Zh. Prikl. Spektrosk., 61, Nos. 3-4, 210–214 (1994).
4. V. S. Letokhov and V. P. Chebotaev, Concepts of Nonlinear Laser Spectroscopy [in Russian], Moscow (1975).
5. V. V. Tuchin, Dynamic Processes in Gas-Discharge Lasers [in Russian], Moscow (1990).