%0 Journal Article
%A I. G. Kozubovskaya
%T Periodic solutions of some systems of nonlinear differential equations
%J Differencialʹnye uravneniâ
%D 1991
%P 705-707
%V 27
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1991_27_4_a20/
%G ru
%F DE_1991_27_4_a20