%0 Journal Article
%A V. E. Chernyshev
%T The existence of saddle periodic solutions of Duffing's equation without dissipation
%J Differencialʹnye uravneniâ
%D 1977
%P 1145-1148
%V 13
%N 6
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1977_13_6_a25/
%G ru
%F DE_1977_13_6_a25