1. Torgova, S.I., Abolin, A.G., Roitman, K.B., Karamysheva, L.A., Ivashchenko, A.V.: Zh. Org. Khim. 24,199 (1988).
2. Ivashchenko, A.V., Torgova, S.I., Karamysheva, L.A., Abolin, A.G.: Liq. Cryst. 7,475 (1990).
3. Mauerhoff, E.: Ph. D. Thesis Halle (1922).
4. Mallon, JJ., Kantor, S.W.: Mol. Cryst. Liq. Cryst. 157,25 (1988).
5. Barnes, PJ., Douglass, A.G., Heeks, S.K., Luckhurst, G.R.: Liq. Cryst. 13,603 (1993).