%0 Journal Article
%A L. A. Cherkas
%T Methods for estimating the number of limit cycles of autonomous systems
%J Differencialʹnye uravneniâ
%D 1977
%P 779-802
%V 13
%N 5
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1977_13_5_a0/
%G ru
%F DE_1977_13_5_a0