@article{2144, author = {Fr\'echet, Maurice}, title = {De l'\'ecart num\'erique \`a l'\'ecart abstrait}, journal = {Portugaliae mathematica}, volume = {5}, year = {1946}, pages = {121-131}, zbl = {0060.39615}, mrnumber = {0016657}, language = {en}, url = {http://dml.mathdoc.fr/item/2144} }
Fréchet, Maurice. De l'écart numérique à l'écart abstrait. Portugaliae mathematica, Tome 5 (1946) pp. 121-131. http://gdmltest.u-ga.fr/item/2144/