VALENCE CHANGE OF EUROPIUM ATOMS DUE TO COLD-WORKING OF MgEu ALLOYS G.K. SHENOY, B.D. DUNLAP, R.C PIRICH and C.R. BURR J. Phys. Colloques, 37 C6 (1976) C6-927-C6-929 DOI: 10.1051/jphyscol:19766199