%0 Journal Article
%A V. A. Il'in
%A A. F. Filippov
%T The character of the spectrum of a selfadjoint extension of the Laplace operator in a bounded region (fundamental 

%J Doklady Akademii Nauk
%D 1970
%P 267-269
%V 191
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1970_191_2_a1/
%G ru
%F DAN_1970_191_2_a1