%0 Journal Article
%A I. I. Pleshkan
%T A new method of research on the isochronism of a system of two differential equations
%J Differencialʹnye uravneniâ
%D 1969
%P 1083-1090
%V 5
%N 6
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1969_5_6_a10/
%G ru
%F DE_1969_5_6_a10