1. N. S. Bakhvalov, Dokl. Akad. Nauk SSSR 221(3), 516 (1975).
2. M. Born and Huang Kun, Dynamical Theory of Crystal Lattices (Clarendon, Oxford, 1954; Inostrannaya Literatura, Moscow, 1958).
3. A. M. Il’in, Mat. Zametki 6(2), 237 (1969).
4. S. M. Kozlov, Math. USSR-Sb. 57(2), 351 (1987).
5. S. A. Nazarov and M. V. Paukshto, Discrete Models and Homogenization in Problems of the Theory of Elasticity (Izd. Leningradsk. Univ., Leningrad, 1984) [in Russian].