1. N. Katsouleas and J. M. Dawson, Phys. Rev. Lett. 51, 392 (1983).
2. C. Joshi, in Radiation in Plasmas (Reviews from 1983 College on Plasma Physics, Trieste, 1983), Ed. by. B. McNamara, (World Scientific, Singapore, 1984), Vol. 1, p. 514.
3. B. E. Gribov, R. Z. Sagdeev, V. D. Shapiro, and V. I. Shevchenko, JETP Lett. 42, 63 (1985).
4. S. V. Bulanov and A. S. Sakharov, Plasma Phys. Rep. 26, 1005 (2000).
5. N. S. Erokhin, A. A. Lazarev, S. S. Moiseev, and R. Z. Sagdeev, Sov. Phys. Dokl. 32, 656 (1987).