@article{ARM_1982__18_3_a2,
     author = {Duda, Jarom{\'\i}r},
     title = {A functional characterization of parallelogram spaces},
     journal = {Archivum mathematicum},
     pages = {129--132},
     publisher = {mathdoc},
     volume = {18},
     number = {3},
     year = {1982},
     mrnumber = {682100},
     zbl = {0515.08004},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ARM_1982__18_3_a2/}
}