1. L. A. Vainshtein, Electromagnetic Waves (Sovetskoe Radio, Moscow, 1957) [in Russian].
2. P. M. Morse and H. Feshbach, Methods of Theoretical Physics (McGraw-Hill, New York, 1953; Inostrannaya Literatura, Moscow, 1960).
3. D. M. Petrov and G. I. Shmel’kova, Vopr. Radioelektron., Ser. Elektron., No. 7, 54 (1967).
4. L. G. Lomize and L. L. Filipchikov, in Proc. Radiotechn. Inst. (RTI, Moscow, 1971), p. 55 [in Russian].
5. N. A. Kogan, B. M. Mashkovtsev, and K. N. Tsibizov, Complex Waveguide Systems (Sudpromgiz, Leningrad, 1963) [in Russian].