@article{10_4064_cm_27_1_89_94,
     author = {J. E. Valentine and S. G. Wayment},
     title = {Metric characterizations of {Banach} spaces},
     journal = {Colloquium Mathematicum},
     pages = {89--94},
     publisher = {mathdoc},
     volume = {27},
     number = {1},
     year = {1973},
     doi = {10.4064/cm-27-1-89-94},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-27-1-89-94/}
}