@article{MZ_1974__139_172124,
     author = {Wilhelm Klingenberg},
     title = {Der {Indexsatz} f\"ur geschlossene {Geod\"atische.}},
     journal = {Mathematische Zeitschrift},
     pages = {231--256},
     publisher = {mathdoc},
     volume = {139},
     year = {1974},
     zbl = {0306.58009},
     url = {http://geodesic.mathdoc.fr/item/MZ_1974__139_172124/}
}