by L.D. Landau and E.M. Lifshitz ; translated from the Russian by J.B. Sykes, J.S. Bell and M.J. Kearsley ; : pbk, : hbk. -- 2nd ed., rev. and enl.. -- Pergamon, 1984. -- (Pergamon international library of science, technology, engineering and social studies . Course of theoretical physics; v. 8).