%0 Journal Article
%A M. A. Krasnosel'skii
%T Periodical solutions in the neighbourhood of a singular point of a dynamical system
%J Doklady Akademii Nauk
%D 1957
%P 180-183
%V 117
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1957_117_2_a4/
%G ru
%F DAN_1957_117_2_a4