%0 Journal Article
%A L. A. Cherkas
%T Absence of cycles in the equation $y'=Q_2(x,y)/P_2(x,y)$, with a focus of third degree of structural instability
%J Differencialʹnye uravneniâ
%D 1976
%P 2281-2282
%V 12
%N 12
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1976_12_12_a22/
%G ru
%F DE_1976_12_12_a22