1. See for example: (a) D.S. Chemla, J. Zyss (Eds.), Nonlinear Optical Properties of Organic Molecules and Crystals, vols. 1 and 2, Academic Press, New York, 1987.
2. (b) R.A. Harm, D. Bloor (Eds.), Organic Materials for Nonlinear Optics, Royal Society of Chemistry, London, 1989.
3. (c) H.S. Nalwa, Appl. Organomet. Chem. 5 (1991) 349.
4. (d) J. Zyss, Molecular Nonlinear Optics, Academic Press, 1994.
5. (e) T.J. Marks, M.A. Ratner, Angew. Chem. Int. Ed. Engl. 34 (1995) 155.