1. See, for instance, IAEA Summary Report (NDS)-82/GB, February 1977.
2. R. N. Il'in, V. A. Oparin, E. S. Solov'ev andN. V. Fedorenko:Sov. Phys. JETP Lett.,2, 197 (1965).
3. J. A. Sellin andL. Granoff:Phys. Lett.,25 A, 484 (1967).
4. W. Grüebler, P. A. Schmelzbach, V. König andP. Marmier:Helv. Phys. Acta,43, 254 (1974).
5. H. Tawara andA. Russek:Rev. Mod. Phys.,45, 178 (1973).