1. Friedel MG (1922) Ann Phys 18:273
2. Wunderlich B, Gerbowicz J (1984) Adv Polym Sci 60/61:1
3. Gray GW (1962) Molecular structure and the properties of liquid crystals. Academic, New York
4. Ciferri A, Krigbaum W, Meyer RB (eds) (1983) Polymer liquid crystals. Academic, New York
5. Gray GW, Winsor PA (eds) (1974) Liquid crystals and plastic crystals. Wiley, Chichester