@article{ELMA_1955__10_140616,
     author = {R. Sauer},
     title = {Elementargeometrische {Modelle} zur {Differentialgeometrie.} {(Schluss).}},
     journal = {Elemente der Mathematik},
     pages = {25--32},
     year = {1955},
     volume = {10},
     zbl = {0064.40702},
     url = {http://geodesic.mathdoc.fr/item/ELMA_1955__10_140616/}
}