TY  - JOUR
AU  - David Ellis
TI  - A Modification of the Parallelogram Law Characterization of Hilbert Spaces.
JO  - Mathematische Zeitschrift
PY  - 1953
SP  - 94
EP  - 96
VL  - 59
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/MZ_1953__59_169376/
ID  - MZ_1953__59_169376
ER  -