%0 Journal Article
%A K. S. Sibirskii
%T Conditions for the presence of a simple saddle-center of an autonomous two-dimensional differential system
%J Differencialʹnye uravneniâ
%D 1986
%P 1456-1458
%V 22
%N 8
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1986_22_8_a22/
%G ru
%F DE_1986_22_8_a22