%0 Journal Article
%A R. R. Akopyan
%T Best approximation of the differentiation operator on the class of functions analytic in a~strip
%J Trudy Instituta matematiki i mehaniki
%D 2014
%P 9-16
%V 20
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/TIMM_2014_20_1_a1/
%G ru
%F TIMM_2014_20_1_a1