%0 Journal Article %A H. Fast %A K. Urbanik %T A characterization of step functions %J Colloquium Mathematicum %D 1959 %P 251-254 %V 7 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/cm-7-2-251-254/ %R 10.4064/cm-7-2-251-254 %G en %F 10_4064_cm_7_2_251_254