1. 1. Libbert, E., Rettig, W. Bonacic-Kutecký, V., Heisel, F., and Miehé, J. A. (1987) Advances in Chemical Physics, eds., I. Prigogine, and S. A. Rice, Wiley-Inter science, New York, 68, 1.
2. 2. Grabowski, Z. R., Rotkiewicz, K., Siemiarczuk, A., Cowley, D. J., and Baumann, W., (1979) Nouv. J. Chim.
3, 433.
3. Rettig, W. Modern models of bonding and delocalization, eds. J. F. Liebman and A. Greenbers (1988) VCH, Weinheim, Ch. 5.
4. 4. Rettig, W. and Baumann, W. (1992) Photochemistry and Photophysics ed. J. F. Rabek, C. R. Press, Boca Raton, FL., 6, 79.
5. 5. Loutfy, R. O., (1981) Macromolecules
14, 270.