%0 Journal Article
%A N. I. Vulpe
%T Coefficient conditions for the number and multiplicity of singular points of a quadratic differential system
%J Differencialʹnye uravneniâ
%D 1991
%P 572-577
%V 27
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1991_27_4_a2/
%G ru
%F DE_1991_27_4_a2