1. J.A. Stratton, Electromagnetic Theory [Russian translation], 1948.
2. N.A. Semenov, NDVSh, Radiotekhnika i elektronika, no. 4, 60, 1958.
3. E. Snitzer, JOSA,51, 491, 1961.
4. F. I. Fedorov, Optics of Anisotropic Media [in Russian], Minsk, 1958.
5. A. M. Goncharenko, Radiotekhnika i elektronika,10, 949, 1965.