@article{CMUC_1999__40_1_a7,
     author = {\c{S}erb, Ioan},
     title = {Rectangular modulus, {Birkhoff} orthogonality and characterizations of inner product spaces},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {107--119},
     publisher = {mathdoc},
     volume = {40},
     number = {1},
     year = {1999},
     mrnumber = {1715205},
     zbl = {1060.46506},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1999__40_1_a7/}
}