1. For a review see for instance: Leray, S.: J. Phys. C4, 275 (1986)
2. Borderie, B.: J. Phys. C4, 251 (1986)
3. Ng�, C., Desbois, J., Nemeth, J., Barranco, M.: Journ�es d'�tudes de Saturne, La Londe les Maures, Novembre 1986, rapport DPhN/Saclay n? 2392 proc. p. 145 (1986)
4. For a review see for instance: H�fner, J.: Phys. Rep.125, 129 (1985); J. Phys.C4, 3 (1986)
5. Csernai, L., Kapusta, J.: Phys. Rep.131, n? 4 (1986)