%0 Journal Article
%A N. P. Korneichuk
%T The exact value of best approximations and widths of certain classes of functions
%J Doklady Akademii Nauk
%D 1963
%P 1218-1220
%V 150
%N 6
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1963_150_6_a7/
%G ru
%F DAN_1963_150_6_a7