1. N. G. Basov, É. M. Belenov, V. A. Danilychev, O. M. Kerimov, I. B. Kovsh, and A. F. Suchkov, Pis'ma Zh. Eksp. Teor. Fiz.,14, 421 (1971).
2. I. P. Shkarofsky, T. W. Johnston, and M. P. Bachynski, The Particle Kinetics of Plasmas, Addison-Wesley (1966).
3. V. L. Ginzburg and A. V. Gurevich, Usp. Fiz. Nauk,70, 201 (1960).
4. V. A. Danilychev, O. M. Kerimov, and I. B. Kovsh, Proceedings of the P. N. Lebedev Physics Institute [in Russian],85, 49?142, (1976).
5. S. D. Rockwood, J. Appl. Phys.,45, 5229?5234 (1974).