ORIGIN OF HYPERFINE FIELDS ACTING ON 155Gd IN (Gd1-xRx) (Co1-yMy)5 (R = RARE EARTH, M = Cu, Ni, Pt) M. Seh, S. Cohen and I. Nowik J. Phys. Colloques, 41 C1 (1980) C1-201-C1-202 DOI: 10.1051/jphyscol:1980162