@article{bwmeta1.element.bwnjournal-article-smv25i1p22bwm,
author = {J. Sch\"affer},
title = {Another characterization of Hilbert spaces},
journal = {Studia Mathematica},
volume = {25},
year = {1965},
pages = {271-276},
zbl = {0128.34501},
language = {en},
url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-smv25i1p22bwm}
}
Schäffer, J. Another characterization of Hilbert spaces. Studia Mathematica, Tome 25 (1965) pp. 271-276. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-smv25i1p22bwm/