%0 Journal Article
%A V. P. Nozdracheva
%T A priori estimation of the length of a closed trajectory on a plane
%J Differencialʹnye uravneniâ
%D 1989
%P 229-233
%V 25
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1989_25_2_a7/
%G ru
%F DE_1989_25_2_a7