%0 Journal Article
%A G. M. Gubreev
%A A. I. Kovalenko
%T Tests for completeness of root subspaces of a differentiation operator with abstract boundary conditions
%J Matematičeskie zametki
%D 1981
%P 543-552
%V 30
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/MZM_1981_30_4_a7/
%G ru
%F MZM_1981_30_4_a7