%0 Journal Article
%A V. S. Ermolin
%T The existence of a definitely positive first integral
%J Differencialʹnye uravneniâ
%D 1976
%P 1123-1124
%V 12
%N 6
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1976_12_6_a18/
%G ru
%F DE_1976_12_6_a18