%0 Journal Article
%A G. I. Shilova
%T The number of periodic solutions of the second kind to the differential equation $\ddot{\varphi}-f_1(\varphi)\dot{\varphi}-f_0(\varphi)=0$
%J Differencialʹnye uravneniâ
%D 1967
%P 1682-1691
%V 3
%N 10
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1967_3_10_a5/
%G ru
%F DE_1967_3_10_a5