%0 Journal Article
%A A. B. Mitel'man
%T The absence of weak lacunae between ovals of the characteristic surface of a~hyperbolic operator
%J Trudy Matematicheskogo Instituta imeni V.A. Steklova
%D 1972
%V 27
%N 6
%I mathdoc
%U http://geodesic.mathdoc.fr/item/RM_1972_27_6_a15/
%G ru
%F RM_1972_27_6_a15