%0 Journal Article
%A V. I. Paškovskii
%T Connected partial differential operators with different principal parts
%J Differencialʹnye uravneniâ
%D 1977
%P 121-125
%V 13
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1977_13_1_a16/
%G ru
%F DE_1977_13_1_a16