%0 Journal Article
%A D. K. Rao
%T Symmetric perturbation of a self-adjoint operator
%J Revista colombiana de matematicas
%D 1973
%P 81-84
%V 7
%I mathdoc
%U http://geodesic.mathdoc.fr/item/RCM_1973__7_181602/
%F RCM_1973__7_181602