%0 Journal Article
%A C.V. Hutton
%T On the Approximation Numbers of an Operator and Its Adjoint.
%J Mathematische Annalen
%D 1974
%P 277-280
%V 210
%I mathdoc
%U http://geodesic.mathdoc.fr/item/MAN_1974__210_162624/
%F MAN_1974__210_162624