1. Tonks, L. and Langmuir, I., Phys. Rev., 1929, vol. 34, p. 876.
2. Bohm, D., in The Characteristics of Electrical Discharges in Magnetic Field, Guthrie, A. and Wakerling, R.K, Eds., New York: McGraw-Hill, 1949, p. 77.
3. Chen, F.F., Introduction to Plasma Physics, New York: Plenum, 1974.
4. Londer, Ya.I. and Ul’yanov, K.N., High Temp., 2013, vol. 51, no. 1, p. 7.
5. Londer, Ya.I. and Ulyanov, K.N., in Proceedings of the 25th International Symposium on Discharges and Electrical Insulation in Vacuum, Tomsk, Russia, September 2–7, 2012, Tomsk, 2012, vol. 2, p. 380.