1. P. de Gennes, The Physics of Liquid Crystals (Clarendon, Oxford, 1974; Mir, Moscow, 1977).
2. Handbook of Liquid Crystals, Ed. by D. Demus et al. (Wiley-VCH, Weinheim, 1998), Vol. 1, p. 790.
3. Physical Properties of Liquid Crystals, Ed. by D. Demus et al. (Wiley-VCH, Weinheim, 1999), p. 59.
4. A. P. Kapustin and O. A. Kapustina, The Acoustics of Liquid Crystals (Nauka, Moscow, 1985) [in Russian].
5. I. Lehman, Kristallisationsmicroscop und die damit gemachten Endeckungen ins besondere die flussigen Kristalle (Braunschhweig, 1910).