%0 Journal Article
%A M. A. Krasnosel'skii
%A V. V. Strygin
%T Some criteria for the existence of periodic solutions of ordinary differential equations
%J Doklady Akademii Nauk
%D 1964
%P 1022-1024
%V 156
%N 5
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1964_156_5_a8/
%G ru
%F DAN_1964_156_5_a8