@article{paperid:1022246,
author = {John M. Rassias and Sal Moslehian, Mohammad},
title = {A characterization of inner product spaces},
journal = {Kochi Journal of Mathematics},
year = {2011},
volume = {6},
number = {1},
month = {March},
issn = {1880-5515},
pages = {101--107},
			numpages = {6},
keywords = {inner product space; Euler--Lagrange identity; Day's
condition; normed space; characterization; operator},
}