1. E. A. Turov, Europhys. Lett. 34(4), 305 (1996).
2. E. A. Turov, A. V. Kolchanov, B. B. Men’shii, et al., Symmetry andPhysical Properties of Antiferromagnets (Fizmatlit, Moscow, 2001) [in Russian].
3. V. D. Buchelnikov and V. G. Shavrov, Zh. Eksp. Teor. Fiz. 109(2), 706 (1996) [JETP 82, 380 (1996)].
4. V. D. Buchelnikov, V. S. Romanov, and V. G. Shavrov, Ferroelectrics 204, 247 (1997).
5. G. S. Krinchik, Physics of Magnetic Phenomena (Izd-vo Mosk. Gos. Univ., Moscow, 1985) [in Russian].