1. A. Bohr and B.R. Mottelson, Nucl. Structure, Vol. 2 (Benjamin N.Y. 1975, 80).
2. J. Pedersen et al., Phys.Rev.Lett.39 (1977) 990.
3. N.C. Singhai et al., Can.J.Phys.57 (1979) 1959.
4. Ogawa et al, Intern. Symp. on High Spin States and Nucl.Structure, Ed. L.Funke, Rossendorf (1977) 31.
5. Z. Méliani et al., Intern. Conf. on Nuclear Structure in the Nineties, Oak Ridge (April 1990).