%0 Journal Article
%A David Ellis
%T A Modification of the Parallelogram Law Characterization of Hilbert Spaces.
%J Mathematische Zeitschrift
%D 1953
%P 94-96
%V 59
%I mathdoc
%U http://geodesic.mathdoc.fr/item/MZ_1953__59_169376/
%F MZ_1953__59_169376