%0 Journal Article
%A M. P. Grigolia
%T A generalization of the characteristic problem for hyperbolic systems
%J Differencialʹnye uravneniâ
%D 1985
%P 678-686
%V 21
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1985_21_4_a14/
%G ru
%F DE_1985_21_4_a14