1. Yu. A. Anan'ev, ?Angular divergence of the radiation of solid-state lasers,? Usp. Fiz. Nauk, 103, No. 4, 705?738.
2. É. M. Belenov, V. N. Morozov, and A. N. Oraevskii, ?Problems of laser dynamics,? Trudy FIAN, 58, 237?336 (1970).
3. A. G. Fox and T. Li, Pros. IRE,48, No. 11, 1904?1905 (1960).
4. A. G. Fox and T. Li, Bell. Syst. Techn. J.,40, No. 2, 453?488 (1961).
5. L. A. Vainshtein, Zh. Eksp. Teor. Fiz.,44, No. 3, 1059?1067 (1963).