1. K. S. Aleksandrov, in Problems of Modern Crystallography (Nauka, Moscow, 1975), p. 327 [in Russian].
2. F. I. Fedorov, Theory of Elastic Waves in Crystals (Nauka, Moscow, 1965; Plenum Press, New York, 1968).
3. M. K. Balakirev and I. A. Gilinskii, Waves in Piezoelectric Crystals (Nauka, Novosibirsk, 1982) [in Russian].
4. H. F. Tiersten, J. Acoust. Soc. Am. 57, 660 (1975).
5. M. P. Zaitseva, Yu. I. Kokorin, Yu. M. Sandler, et al., Nonlinear Electromechanical Properties of Acentric Crystals (Nauka, Novosibirsk, 1986) [in Russian].