%0 Journal Article
%A P. I. Plotnikov
%T Equations with a variable direction of parabolicity and the
%J Doklady Akademii Nauk
%D 1993
%P 691-693
%V 330
%N 6
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1993_330_6_a4/
%G ru
%F DAN_1993_330_6_a4