1. K. S. Aleksandrov, N. V. Fedoseeva, and I. P. Spevakova, Magnetic Phase Transitions in Haloid Crystals, Collected vol. (Nauka, Novosibirsk, 1983), ch. 2, p. 48 [in Russian].
2. M. A. Aldzhanov, N. G. Guseinov, G. D. Sultanov, and M. D. Nadzafzade, Phys. Stat. Solidi B 159, K107 (1990).
3. M. A. Aldzhanov, A. A. Abdurragimov, S. G. Sultanova, and M. D. Nadzhafzade, Fiz. Tverd. Tela 49, 309 (2007) [Phys. Solid State 49, 320 (2007)].
4. M. Aljanov, M. Nadjafzade, Z. Seidov, and M. Gasumov, Turkish J. Phys. 20, 1071 (1996).
5. A. Kutoglu, Naturwissenchaften B 61(3), 125 (1974).