GAMMA-RAY TRANSITION ENERGY CORRELATIONS IN 156Er AND 160Yb J.P. Vivien, Y. Schutz, F.A. Beck, T. Byrski, C. Gehringer and J.C. Merdinger. J. Phys. Colloques, 41 C10 (1980) C10-135-C10-138 DOI: 10.1051/jphyscol:19801013