X-RAY ABSORPTION STUDIES OF MIXED-VALENT RARE EARTH CLUSTERS W. NIEMANN, W. MALZFELDT, P. RABE et M. LÜBCKEJ. Phys. Colloques, 47 C8 (1986) C8-931-C8-935DOI: https://doi.org/10.1051/jphyscol:19868179