%0 Journal Article
%A I. I. Ibragimov
%A I. F. Kushnirchuk
%T On the completeness of the system of eigenfunctions of a class of partial differential operators
%J Doklady Akademii Nauk
%D 1975
%P 1020-1023
%V 222
%N 5
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1975_222_5_a1/
%G ru
%F DAN_1975_222_5_a1