%0 Journal Article
%A E. V. Voskresenskii
%T Sharpening of a theorem of Levinson
%J Differencialʹnye uravneniâ
%D 1988
%P 1455-1457
%V 24
%N 8
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1988_24_8_a21/
%G ru
%F DE_1988_24_8_a21