Galaxy population in distant galaxy clusters. I. Cl 0939+472 (z=0.41) and Cl 0016+161 (z=0.54)P. Belloni and H.-J. RöserAstron. Astrophys. Suppl. Ser., 118 1 (1996) 65-87DOI: https://doi.org/10.1051/aas:1996182