%0 Journal Article %A Monika Herzog %T Approximation of functions of two variables by modified Szasz-Mirakyan operators %J Commentationes Mathematicae %D 2012 %P 3-9 %V 52 %N 1 %U http://geodesic.mathdoc.fr/articles/10.14708/cm.v52i1.5322/ %R 10.14708/cm.v52i1.5322 %G pl %F 10_14708_cm_v52i1_5322