1. See for example J. M. Williams, J. M. Ferraro, R. J. Thorn, K. D. Carlson, U. Geiser, H. H. Wang, A. M. Kini, and M. H. Whangbo: Organic superconductors. Synthesis, Structure, Properties and Theory ,R. N. Grimes (ed.), Prentice Hall, Englewood Cliffs, New Jersey (1992).
2. Gatteschi, O. Kahn, J. S. Miller, and F. Palacio (eds.): Magnetic Molecular Materials ,NATO ASI Series E198. Kluwer Academic Publishers: Dordrecht, Holland (1991).
3. D. S. Chelma, J. Zyss (eds.): Nonlinear Optical Properties of Organic Molecules and Crystals ,Academic Press: Orlando, (1987).
4. J. S. Miller: Adv. Mater. 2, 98, (1990).
5. This topic is discussed in the contribution of N. Casafi and L. C. W. Baker in this volume.