@article{MAN_1882__19_156996,
     author = {B\"acklund},
     title = {Zur {Theorie} der {Fl\"achentransformationen.}},
     journal = {Mathematische Annalen},
     pages = {387--422},
     publisher = {mathdoc},
     volume = {19},
     year = {1882},
     zbl = {13.0296.01},
     url = {http://geodesic.mathdoc.fr/item/MAN_1882__19_156996/}
}