%0 Journal Article %A Krystyna Skórnik %T On functions with vanishing local derivative %J Annales Polonici Mathematici %D 1986 %P 179-188 %V 47 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/ap-47-2-179-188/ %R 10.4064/ap-47-2-179-188 %G en %F 10_4064_ap_47_2_179_188