%0 Journal Article
%A G. A. Isaev
%T On the theory of defect indices for multiparameter differential operators of Sturm--Liouville type
%J Doklady Akademii Nauk
%D 1981
%P 788-791
%V 261
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1981_261_4_a3/
%G ru
%F DAN_1981_261_4_a3