%0 Journal Article
%A È. V. Vdovina
%T Some theorems on limit cycles
%J Differencialʹnye uravneniâ
%D 1967
%P 2053-2057
%V 3
%N 12
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1967_3_12_a5/
%G ru
%F DE_1967_3_12_a5