%0 Journal Article %A Phillips, Ralph S. %T Semi-groups of positive contraction operators %J Czechoslovak Mathematical Journal %D 1962 %P 294-313 %V 12 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.21136/CMJ.1962.100517/ %R 10.21136/CMJ.1962.100517 %G en %F 10_21136_CMJ_1962_100517