1. Yu. A. Romanov, Zh. Éksp. Teor. Fiz.,47, No. 6, 2119 (1964).
2. K. N. Stepanov, Zh. Tekhn. Fiz.,35, No. 6, 1002 (1965).
3. A. N. Kondratenko, Plasma Waveguides [in Russian], Atomizdat, Moscow (1976).
4. A. R. Barakate, V. V. Dolgopolov, and N. M. El-Siragy, Plasma Physics,17, No. 1, 89 (1975).
5. V. M. Kuklin, I. P. Panchenko, and V. M. Chernousenko, Dokl. Akad. Nauk Ukr. SSR, Ser. A, Fiz.-Mat. Tekhn. Nauki, No. 9, 52 (1988).