1. C. W. Oseen:Ark. Mat. Astron. Fys. A,19, 1 (1925);Trans. Faraday Soc.,29, 883 (1933);F. C. Frank:Discuss. Faraday Soc.,25, 19 (1958);E. B. Priestley, P. J. Wojtowicz andPing Shen:Introduction to Liquid Crystals, (Plenum Press, New York, N.Y., 1974). p. 143, and references therein;P. G. de Gennes:The Physics of Liquid Crystals (Clarendon Press, Oxford, 1974), p. 59, and references therein;S. Chandrasekhar:Liquid Crystals (Cambridge University Press, Cambridge, 1977), p. 98, and references therein.
2. J. Nehring andA. Saupe:J. Chem. Phys.,54, 337 (1971).
3. J. Nehring andA. Saupe:J. Chem. Phys.,56, 5527 (1972).
4. E. Dubois-Violette andO. Parodi:J. Phys. (Paris) Colloq.,30, C4–57 (1969).
5. D. W. Berreman andS. Meiboom:Phys. Rev. A.,30, 1955 (1984).