%0 Journal Article
%A V. V. Amel'kin
%T Existence of limit cycles of two-dimensional autonomous systems of differential equations
%J Differencialʹnye uravneniâ
%D 1988
%P 2027-2032
%V 24
%N 12
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1988_24_12_a0/
%G ru
%F DE_1988_24_12_a0