1. Yu. Schwinger, Zarubezh, Radioelektron., No. 3, 6 (1970).
2. C. M. Angulo and W. S. C. Chang, IRE Trans.AP-7, No. 3, 207 (1959).
3. R. E. Collin, Field Theory of Guided Waves, McGraw-Hill, New York (1960).
4. A. B. Manenkov, Izv. Vyssh. Uchebn. Zaved., Radiofizika,13, No. 5, 739 (1970).
5. A. B. Manenkov, Izv. Vyssh. Uchebn. Zaved., Radiofizika,24, No. 1, 84 (1981).