1. Ya. B. Zel'dovich and Yu. P. Raizer, The Physics of Shock Waves and High-Temperature Hydrodynamic Phenomena [in Russian], Izd. Nauka, Moscow (1966).
2. V. D. Rusanov, Modern Methods of Plasma Research [in Russian], Gosatomizdat (1962).
3. F. L. Mohler and C. Boeckner, Nat. Bur. Stand. J.,2, 489 (1929).
4. H. Edels, ?Determination of the temperature of an electric gas discharge,? in: Optical Pyrometry of Plasmas [Russian translation], N. N. Sobolev (editor), IL, Moscow (1960).