@article{MAN_1926__95_159133,
     author = {H. Hopf},
     title = {Zum {Clifford-KIeinschen} {Raumproblem}},
     journal = {Mathematische Annalen},
     pages = {313--339},
     publisher = {mathdoc},
     volume = {95},
     year = {1926},
     language = {de},
     url = {http://geodesic.mathdoc.fr/item/MAN_1926__95_159133/}
}