@article{JRAM_1931__164_149747,
     author = {Otto Haupt},
     title = {\"Uber die {Struktur} reeller {Kurven.}},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {50--60},
     publisher = {mathdoc},
     volume = {164},
     year = {1931},
     zbl = {0001.17202},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1931__164_149747/}
}