@article{MAN_1912__71_158521,
     author = {M. Dehn},
     title = {\"Uber unendliche diskontinuierliche {Gruppen.} {(Mit} 5 {Figuren} im {Text).}},
     journal = {Mathematische Annalen},
     pages = {116--144},
     publisher = {mathdoc},
     volume = {71},
     year = {1912},
     zbl = {42.0508.03},
     url = {http://geodesic.mathdoc.fr/item/MAN_1912__71_158521/}
}