%0 Journal Article %A Mustafa Akcoglu %T Positive Contractions of L2-Spaces. %J Mathematische Zeitschrift %D 1975 %P 5-14 %V 143 %I mathdoc %U http://geodesic.mathdoc.fr/item/MZ_1975__143_172207/ %F MZ_1975__143_172207