@article{AM2_1969__2_182333,
     author = {O. HAUPT},
     title = {Ein allgemeiner {Vierscheitelsatz} f\"ur ebene {Jordankurven}},
     journal = {Aequationes mathematicae},
     pages = {248--264},
     publisher = {mathdoc},
     volume = {2},
     year = {1969},
     zbl = {0174.24601},
     url = {http://geodesic.mathdoc.fr/item/AM2_1969__2_182333/}
}