%0 Journal Article
%A Rempulska, Lucyna
%A Tomczak, Karolina
%T On approximation of functions by certain operators preserving $x^2$
%J Commentationes Mathematicae Universitatis Carolinae
%D 2008
%P 579-593
%V 49
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/CMUC_2008__49_4_a4/
%G en
%F CMUC_2008__49_4_a4