1. G. Frencis, in Handbuch der Physik, Ed. by S. Flugge (Springer-Verlag, Berlin, 1956), Vol. 22, p. 53.
2. V. L. Granovskii, Electric Current in a Gas: Steady-State Current (Nauka, Moscow, 1971).
3. Yu. P. Raizer, Teplofiz. Vys. Temp. 24, 984 (1986).
4. V. N. Melekhin and N. Yu. Naumov, Pis’ma Zh. Tekh. Fiz. 12, 99 (1986) [Sov. Tech. Phys. Lett. 12, 41 (1986)].
5. Yu. P. Raizer and S. T. Surzhikov, Pis’ma Zh. Tekh. Fiz. 13, 452 (1987) [Sov. Tech. Phys. Lett. 13, 186 (1987)].