1. A. von Engel, Ionized Gases (Clarendon, Oxford, 1965; Mir, Moscow, 1968).
2. V. L. Granovskiĭ, Electric Current in a Gas: Steady-State Current (Nauka, Moscow, 1971) [in Russian].
3. Yu. P. Raizer, Gas Discharge Physics (Nauka, Moscow, 1987; Springer-Verlag, Berlin, 1991).
4. Gaseous Electronics, Ed by M. N. Hirsh and H. J. Oskam (Academic, New York, 1978), Vol. 1, Chap. 2.
5. A. M. Howatson, An Introduction to Gas Discharges (Pergamon, Oxford, 1965).