%0 Journal Article
%A Yu. V. Egorov
%A P. R. Popivanov
%T A class of pseudodifferential equations of principal type having no solutions
%J Doklady Akademii Nauk
%D 1973
%P 775-777
%V 209
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1973_209_4_a4/
%G ru
%F DAN_1973_209_4_a4