@article{GDZPPN002259915, title = {A characteristic property of isothermal systems of curves}, journal = {Mathematische Annalen}, volume = {58}, year = {1904}, pages = {352-354}, zbl = {35.0622.03}, url = {http://dml.mathdoc.fr/item/GDZPPN002259915} }
Kasner, Edward. A characteristic property of isothermal systems of curves. Mathematische Annalen, Tome 58 (1904) pp. 352-354. http://gdmltest.u-ga.fr/item/GDZPPN002259915/