1. S. A. Slutz, C. L. Olson, and P. Peterson, Phys. Plasmas 10, 429 (2003).
2. Yu. G. Kalinin, A. V. Korel’skiĭ, E. V. Kravchenko, and A. Yu. Shashkov, Kvantovaya Élektron. (Moscow), 34, 399 (2004).
3. É. P. Kruglyakov, in Plasma Diagnostics, Ed. by S. Yu. Luk’yanov (Atomizdat, Moscow, 1973), Vol. 3, p. 97 [in Russian].
4. A. B. Mikhailovskii, Electromagnetic Instabilities in an Inhomogeneous Plasma (Atomizdat, Moscow, 1975; Institute of Physics, Bristol, 1992).
5. A. V. Batjunin, A. N. Bulatov, A. V. Branitskij, et al., in Proceedings of the 8th International Conference on High-Power Particle Beams, Novosibirsk, 1990, Vol. 2, p. 1091.