@article{MZ_1952__56_169284,
     author = {Frank L\"obell},
     title = {Nat\"urliche {Geometrie} der {Kurvenkongruenzen.}},
     journal = {Mathematische Zeitschrift},
     pages = {208--218},
     publisher = {mathdoc},
     volume = {56},
     year = {1952},
     language = {de},
     url = {http://geodesic.mathdoc.fr/item/MZ_1952__56_169284/}
}