%0 Journal Article
%A S. B. Vakarchuk
%T Best Polynomial Approximations and Widths of Classes of Functions in the Space~$L_2$
%J Matematičeskie zametki
%D 2018
%P 307-311
%V 103
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/MZM_2018_103_2_a12/
%G ru
%F MZM_2018_103_2_a12