%0 Journal Article
%A L. A. Beklaryan
%T A new approach to the question of existence of periodic solutions

%J Izvestiya. Mathematics 
%D 2018
%P 1077-1107
%V 82
%N 6
%I mathdoc
%U http://geodesic.mathdoc.fr/item/IM2_2018_82_6_a0/
%G en
%F IM2_2018_82_6_a0