%0 Journal Article
%A S. L. Sobolev
%T Representation of periodic analytic functions by a sum of squares
%J Doklady Akademii Nauk
%D 1965
%P 40-43
%V 165
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1965_165_1_a10/
%G ru
%F DAN_1965_165_1_a10