@article{GDZPPN002255243, title = {Sur la th\'eorie g\'en\'erale des surfaces unicursales}, journal = {Mathematische Annalen}, volume = {44}, year = {1894}, pages = {428-445}, zbl = {25.1227.02}, url = {http://dml.mathdoc.fr/item/GDZPPN002255243} }
Humbert, M.G. Sur la théorie générale des surfaces unicursales. Mathematische Annalen, Tome 44 (1894) pp. 428-445. http://gdmltest.u-ga.fr/item/GDZPPN002255243/