@article{ARM_1996__32_3_a6,
     author = {Alsina, C. and Guijarro, P. and Tom\'as, M. S.},
     title = {Characterizations of inner product structures involving the radius of the inscribed or circumscribed circumference},
     journal = {Archivum mathematicum},
     pages = {233--239},
     publisher = {mathdoc},
     volume = {32},
     number = {3},
     year = {1996},
     mrnumber = {1421858},
     zbl = {0909.46020},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ARM_1996__32_3_a6/}
}