1. Budden, K.G.; Radion Waves in the Ionosphere. Cambridge Univ., Cambridge 1961.
2. Ginzburg, W.L.; Propagation of Electromagnetic Waves in Plasmas. Pergamon Press, New York 1964.
3. White, R.B., Chen, F.F.; Plasma Phys. 16 (1974) 565.
4. Forslund, D.W., Kindel, J.M., Lee, K., Lindman, E.L., Morse, R.L.; Phys. Rev. A11, 679(1975).
5. Denisov, N.G.; Zh. Eksp. Teor. Fiz. 31, 609(1956).