1. P. N. Prasad and D. J.Williams, Introduction to Nonlinear Optical Effects in Molecules and Polymers, Wiley, New York, 1991;
2. D. S. Chemla and J. Zyss, eds., Nonlinear Optical Properties of Organic Molecules and Crystals, vols. 1 and 2, Academic Press, London, 1987;
3. J. Zyss, ed., Molecular Nonlinear Optics, Academic Press, 1994.
4. C. W. Bird and G. W. H.Cheeseman, in Comprehensive Heterocyclic Chemistry, vol. 4, Pergamon Press, 1984, pp. 28–30.
5. Calculated hyperpolarisabilities of polythiophenes, polyfurans and polypyrroles