1. M. Born and E. Wolf, Principles of Optics: Electromagnetic Theory of Propafation, Interference, and Diffraction of Light (Pergamon, Oxford, 1964).
2. Yu. V. Troitskii, One-Particle Generation in Gas Lasers (Nauka, Novosibirsk, 1975) [in Russian].
3. Yu. V. Troitskii, Sov. J. Quantum Electron. 5, 1331 (1975).
4. A. A. Kovalyov, V. V. Preobrazhenskii, M. A. Putyato, O. P. Pchelyakov, and N. N. Rubtsova, Izv. Akad. Nauk 72, 771 (2008).