%0 Journal Article %A M. Kuczma %T On the functional equation f(x + y) — f(x) + f (y) %J Fundamenta Mathematicae %D 1961 %P 387-391 %V 50 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/fm-50-4-387-391/ %R 10.4064/fm-50-4-387-391 %G en %F 10_4064_fm_50_4_387_391