%0 Journal Article
%A A. A. Reinfeld
%T The reduction theorem for closed trajectories
%J Differencialʹnye uravneniâ
%D 1975
%P 1811-1818
%V 11
%N 10
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1975_11_10_a10/
%G ru
%F DE_1975_11_10_a10