1. L. Asch, Physica B 161 (1989) 299.
2. A. Kratzer, PhD Thesis, Technical University Munich 1989.
3. J. Rossat-Mignod, G.H. Lander and P. Burlet,Handbook Phys. Chem. Actinides, Vol. 1, eds. A.J. Freeman and G.H. Lander (North-Holland, 1984) p. 415.
4. Y.J. Uemura, UT-MSL Report Nr20 (1981).
5. K.W. Kehr, G. Honig and D. Richter, Z. Phys. B 32 (1978) 49.