%0 Journal Article
%A A. M. Krasnosel'skii
%T On forced periodic oscillations in the nonlinear systems
%J Doklady Akademii Nauk
%D 1984
%P 1356-1359
%V 276
%N 6
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1984_276_6_a18/
%G ru
%F DAN_1984_276_6_a18