%0 Journal Article %A T. Styƛ %T The maximum principle for the systems of the difference equations %J Annales Polonici Mathematici %D 1968 %P 223-230 %V 20 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/ap-20-3-223-230/ %R 10.4064/ap-20-3-223-230 %G en %F 10_4064_ap_20_3_223_230