1. A. Lau, W. Werncke, M. Pfeiffer: Spectrochimica Acta Rev. 13, 191 (1990)
2. G. Scheibe, J. Heiss, K. Feldmann: Ber. Bunsenges. Phys. Chem. 70, 52 (1966)
3. S. Rentsch, R.V. Danelius, R.A. Gadonas: Chem. Phys. 59, 119 (1981)
4. A. Lau, W. Werncke, M. Pfeiffer, H.-J. Weigmann, Kim Man Bok: J. Raman Spectrosc. 19, 517 (1988)
5. H. Hartmann, P. Wähner: Abstracts “Fourth Symposium Optical Spectroscopy” October 1986, Reinhardsbrunn, GDR.