1. V. G. Bar’yakhtar, E. V. Zarochentsev, E. P. Troitskaya, and Yu. V. Eremeichenkova, Fiz. Tverd. Tela (St. Petersburg) 40(8), 1464 (1998) [Phys. Solid State 40, 1330 (1998)].
2. Yu. V. Eremeichenkova, E. V. Zarochentsev, and E. P. Troitskaya, Teor. Mat. Fiz. 102(3), 498 (1996).
3. E. V. Zarochentsev and E. P. Troitskaya, Fiz. Tverd. Tela (Leningrad) 27(8), 2474 (1985) [Sov. Phys. Solid State 27, 1480 (1985)].
4. F. Birch, J. Geophys. Res. 57, 227 (1952).
5. R. E. Cohen, O. Gulseren, and R. J. Hemley, cond-mat/9905389.