%0 Journal Article
%A V. P. Shatskii
%T On hyperbolic systems with two planes of singularities
%J Doklady Akademii Nauk
%D 1978
%P 56-59
%V 242
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1978_242_1_a12/
%G ru
%F DAN_1978_242_1_a12