1. V.M. Chaikowskii, L.L. Mineev and I.I. Sushkin,Proc. All-Union Conf. on Liquid Crystals. Ivanovo, 1985, Vol. 1(1), p. 16.
2. R.A. Stukan, S.P. Gubin, A.N. Nesmeyanov, V.I. Goldanskii and E.F. Makarov, Teor. Eksp. Khim. 2 (1966) 805.
3. V.Ya. Rochev, N.K. Kivrina and O.P. Kevdin, Acta Phys. Pol. 56A (1979) 137.
4. V.Ya. Rochev, Adv. Liq. Cryst. 5 (1982) 79.
5. D.L. Uhrich, in.Chemical Mössbauer Spectroscopy, ed. R.H. Herber (New-York, London, Plenum Press, 1984) p. 243.