@article{JRAM_1924__153_149529,
     author = {Rudolf Sturm},
     title = {Ein- und {Zweischaligkeit} von {Fl\"achen} 3. {Ordnung.}},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {1--7},
     publisher = {mathdoc},
     volume = {153},
     year = {1924},
     zbl = {49.0477.01},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1924__153_149529/}
}