@article{MAN_1880__16_156902,
     author = {Voss},
     title = {Geometrische {Interpretation} der {Differentialgleichnng} {P} d x + {Qdy} + {Rdz} = 0},
     journal = {Mathematische Annalen},
     pages = {556--559},
     year = {1880},
     volume = {16},
     zbl = {12.0278.01},
     url = {http://geodesic.mathdoc.fr/item/MAN_1880__16_156902/}
}