@article{PORMA_1946__5_2_114634,
     author = {Fr\'echet, Maurice},
     title = {De l'\'ecart num\'erique \`a l'\'ecart abstrait},
     journal = {Portugaliae mathematica},
     pages = {121--131},
     publisher = {mathdoc},
     volume = {5},
     number = {2},
     year = {1946},
     mrnumber = {0016657},
     zbl = {0060.39615},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PORMA_1946__5_2_114634/}
}