%0 Journal Article
%A M. V. Deikalova
%T Several extremal approximation problems for the characteristic function of a~spherical layer
%J Trudy Instituta matematiki i mehaniki
%D 2011
%P 122-135
%V 17
%N 3
%I mathdoc
%U http://geodesic.mathdoc.fr/item/TIMM_2011_17_3_a13/
%G ru
%F TIMM_2011_17_3_a13