1. M. Piltch, W. T. Walter, N. Solimene, et al., Bull. Am. Phys. Soc. 11(1), 113 (1966).
2. G. G. Petrash, Usp. Fiz. Nauk 105, 645 (1971) [Sov. Phys. Usp. 14, 747 (1971)].
3. A. G. Grigor’yants, M. A. Kazaryan, and N. A. Lyabin, Copper Vapor Lasers: Design, Parameters, and Application (Fizmatlit, Moscow, 2005) [in Russian].
4. G. G. Petrash, Optical Systems with Brightness Amplifiers (Nauka, Moscow, 1991) [in Russian].
5. K. I. Zemskov, A. A. Isaev, M. A. Kazaryan, et al., Kvantovaya Élektron. 1, 13 (1974).