1. A. D. Gladun, Elektron. Tekhnika, No. 8, 39 (1966).
2. M. H. Miller, J. Appl. Phys. 32 (9), 1791 (1961).
3. P. D. Kravchenya, Candidate’s Dissertation in Mathematics and Physics (Volgograd, 2014).
4. S. P. Kuznetsov, Zh. Tekh. Fiz. 47 (12), 2483 (1977).
5. R. H. Levy, Phys. Fluids 8 (7), 1288 (1965).