1. M. A. Leontovich,Izv. Akad. Nauk SSSR, Ser. Fiz. 8, No. 1, 16 (1944).
2. M. A. Leontovich and V. A. Fok,Zh. Eksp. Teor. Fiz. 16, No. 7, 557 (1946).
3. L. A. Vainshtein,Open Cavities and Open Waveguides [in Russian], Sov. Radio, Moscow (1966).
4. N. G. Kondratenko and V. I. Talanov,Izv. Vyssh. Uchebn. Zaved., Radiofiz. 7, No. 2, 313 (1964).
5. V. I. Bespalov, A. G. Litvak, and V. I. Talanov,Self-Action of Electromagnetic Waves in Cubic Isotropic Media, Nonlinear Optics [in Russian], Nauka, Novosibirsk (1968).