@article{JRAM_1889__104_148749,
     author = {R. von Lilienthal},
     title = {Zur {Kr\"ummungstheorie} der {Fl\"achen.}},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {341--344},
     publisher = {mathdoc},
     volume = {104},
     year = {1889},
     zbl = {21.0752.01},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1889__104_148749/}
}