%0 Journal Article %A K. Urbanik %T Effective processes in the sense of H. Steinhaus %J Studia Mathematica %D 1958 %P 335-348 %V 17 %N 3 %U http://geodesic.mathdoc.fr/articles/10.4064/sm-17-3-335-348/ %R 10.4064/sm-17-3-335-348 %G en %F 10_4064_sm_17_3_335_348