%0 Journal Article
%A V. V. Amel'kin
%T Classification of limit cycles
%J Differencialʹnye uravneniâ
%D 1991
%P 1291-1296
%V 27
%N 8
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1991_27_8_a0/
%G ru
%F DE_1991_27_8_a0