%0 Journal Article
%A J.J. Schäffer
%T Linear Differential Equations and Functional Analysis. V.
%J Mathematische Annalen
%D 1960
%P 308-321
%V 140
%I mathdoc
%U http://geodesic.mathdoc.fr/item/MAN_1960__140_160782/
%F MAN_1960__140_160782