%0 Journal Article %A Ryotaro Sato %T A mean ergodic theorem for a contraction semigroup in Lebesgue space %J Studia Mathematica %D 1975 %P 213-219 %V 54 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/sm-54-3-213-219/ %R 10.4064/sm-54-3-213-219 %G en %F 10_4064_sm_54_3_213_219