%0 Journal Article
%A V. Ya. Ivrii
%T A certain class of nonstrictly hyperbolic operators
%J Differencialʹnye uravneniâ
%D 1973
%P 299-306
%V 9
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1973_9_2_a11/
%G ru
%F DE_1973_9_2_a11