%0 Journal Article
%A L. S. Pontryagin
%A L. V. Rodygin
%T Periodic solution of a system of ordinary differential equations with a small parameter in the terms containing derivatives
%J Doklady Akademii Nauk
%D 1960
%P 537-540
%V 132
%N 3
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1960_132_3_a13/
%G ru
%F DAN_1960_132_3_a13