1. B. N. Grechushnikov, Modern Crystalography, Ed. by B. K. Vainshtein (Nauka, Moscow, 1981) [in Russian], p. 338.
2. W. Voigt, Kompendium der theoretische Physik (Leipzig, 1896).
3. P. Drude, Optics (ONTI, Moscow, 1935) [in Russian].
4. F. I. Fedorov, Optics of Anisotropic Media (Akad. Nauk BSSR, Minsk, 1958) [in Russian].
5. A. M. Goncharenko, Candidate’s Dissertation in Physics and Mathematics (Minsk, 1960).