1. A.S. Sonin, A Way Century Long. History of Discovery and Study of Liquid Crystals (Nauka, Moscow, 1988), p. 224 (in Russian)
2. G.H. Brown, J.J. Wolken, Liquid Crystals and Biological Structures (Academic Press, New York, 1979), p. 316
3. N.V. Usol’tseva, O.B. Okopova, V.V. Bikova, A.I. Smirnova, S.A. Pikin, Liquid Crystals: Discotic Mesogens (University Publishers, Ivanovo, 2004), p. 546 (in Russian)
4. S. Kumar (ed.), Liquid Crystals: Experimental Study of Physical Properties and Phase Transitions (University Press, Cambridge, 2000), p. 494
5. H. Kitzerow, C. Bahr, Chirality in Liquid Crystals. Series: Partially Ordered Systems (Springer Verlag, Berlin-Heidelberg-New York, 2001), p. 234