%0 Journal Article
%A V. V. Arestov
%T Best approximation of differentiation operators
%J Matematičeskie zametki
%D 1967
%P 149-154
%V 1
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/MZM_1967_1_2_a2/
%G ru
%F MZM_1967_1_2_a2