%0 Journal Article
%A J.J. Schäffer
%T Linear Differential Equations and Functional Analysis. VI.
%J Mathematische Annalen
%D 1962
%P 354-400
%V 145
%I mathdoc
%U http://geodesic.mathdoc.fr/item/MAN_1962__145_160915/
%F MAN_1962__145_160915