1. Krien, K., Djadali, F., Naumann, R.A., Hübel, H., Spejewski, E.H.: Phys. Rev. C7, 2484 (1973)
2. Jansen, J.F.W., Sujkowski, Z., Chmielewska, D., de Meijer, R.J.: Proc. 3rd Int. Conf. on nuclei far from stability ? Cargese May 1976, CERN 76-13, 415
3. Bowman, W.W., Haenni, D.R., Sugihara,T.T.: texas A.G.M., Progress Report, (1972?1973), 30
4. Aguer, P., Bastin, G., Thibaud, J.P., Barneoud, D., Boutet, J., Foin, C.: J. Phys. G: Nucl. Phys. Vol. 3, N? 7, L1 (1977)
5. Iachello, F., Arima, A.: Phys. Lett.53B, 309 (1974)