NATURE OF 4f ELECTRONS IN Tb OXIDES BY X-RAY ABSORPTION SPECTROSCOPY J.M. ESTEVA, R.C. KARNATAK, H. DEXPERT, M. GASGNIER, P.E. CARO et L. ALBERT J. Phys. Colloques, 47 C8 (1986) C8-955-C8-959 DOI: 10.1051/jphyscol:19868183