%0 Journal Article
%A V. A. Lunkevich
%A K. S. Sibirskii
%T Conditions for a center in the case of homogeneous nonlinearities of third degree
%J Differencialʹnye uravneniâ
%D 1965
%P 1482-1487
%V 1
%N 11
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1965_1_11_a4/
%G ru
%F DE_1965_1_11_a4