1. A. Gorlitz et al., Phys. Rev. Lett., 87, 130402 (2001).
2. V. V. Skobelev, Teor. Mat. Fiz., 161, No. 1, 1385 (2009).
3. L. D. Landau and E. M. Lifshitz, Theoretical Physics, Vol. 2, The Classical Theory of Fields, Fourth Edition, Butterworth-Heinemann, London (1975).
4. N. Ya. Vilenkin, Special Functions and the Theory of Representations of Groups [in Russian], Nauka, Main Editorial Office of Physical and Mathematical Literature, Moscow (1965).
5. G. A. Korn and T. M. Korn, Mathematical Handbook for Scientists and Engineers: Definitions, Theorems, and Formulas for Reference and Review, Second Edition, McGraw-Hill, New York (1968).