@article{MAN_1904__59_158158, author = {Edward Kasner}, title = {A characteristic property of isothermal systems of curves}, journal = {Mathematische Annalen}, pages = {352--354}, publisher = {mathdoc}, volume = {59}, year = {1904}, zbl = {35.0622.03}, url = {http://geodesic.mathdoc.fr/item/MAN_1904__59_158158/} }