%0 Journal Article
%A I. A. Grigor'eva
%T A generalization of Bernstein’s theorem on the form of nonnegative trigonometric polynomials to the case of 

%J Doklady Akademii Nauk
%D 1962
%P 283-286
%V 147
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1962_147_2_a3/
%G ru
%F DAN_1962_147_2_a3