%0 Journal Article %A Kim, Choo-Whan %T Approximations of contraction operators on $L^\infty $ - I %J Portugaliae mathematica %D 1979 %P 213-232 %V 38 %N 3-4 %I mathdoc %U http://geodesic.mathdoc.fr/item/PORMA_1979__38_3-4_115405/ %G en %F PORMA_1979__38_3-4_115405