%0 Journal Article
%A V. V. Amel'kin
%T The periodic solutions of a certain class of nonlinear systems
%J Differencialʹnye uravneniâ
%D 1969
%P 385-388
%V 5
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1969_5_2_a18/
%G ru
%F DE_1969_5_2_a18