1. I. Sh. Akhmadullin, S. A. Migachev, M. F. Sadykov, and M. M. Shakirzyanov, Fiz. Tverd. Tela (St. Petersburg) 46(2), 305 (2004) [Phys. Solid State 46, 312 (2004)].
2. E. A. Turov, Zh. Éksp. Teor. Fiz. 96(6), 2140 (1989) [Sov. Phys. JETP 69, 1211 (1989)].
3. V. I. Ozhogin and V. L. Preobrazhenskii, Usp. Fiz. Nauk 155(4), 593 (1988) [Sov. Phys. Usp. 31, 713 (1988)].
4. E. A. Turov, A. V. Kolchanov, V. V. Men’shikov, I. F. Mirsaev, and V. V. Nikolaev, Symmetry and Physical Properties of Antiferromagnets (Fizmatlit, Moscow, 2001) [in Russian].
5. A. S. Borovik-Romanov and E. G. Rudashevskii, Zh. Éksp. Teor. Fiz. 47(6), 2095 (1964) [Sov. Phys. JETP 20, 1407 (1964)].