1. A. E. Dubinov and V. D. Selemir, Radiotekh. Élektron. (Moscow) 47, 645 (2002).
2. A. E. Dubinov, I. Yu. Kornilova, and V. D. Selemir, Usp. Fiz. Nauk 172(11), (2002) [Phys. Usp. (2002)] (in press).
3. V. Bursian and V. Pavlov, Journal of the Russian Physico-Chemical Society 55(1–3), 71 (1923).
4. S. D. Gvozdover, Theory of Microwave Electronic Devices (GITTL, Moscow, 1956).
5. A. V. Pashchenko, B. N. Rutkevich, V. D. Fedorchenko, and Yu. P. Mazalov, Zh. Tekh. Fiz. 53, 75 (1983) [Sov. Phys. Tech. Phys. 28, 42 (1983)].