@article{MAN_1933__107_159584,
     author = {H. Hopf and W. Binow},
     title = {Die topologischen {Gestalten} differentialgeometrisch verwandter {Fl\"achen}},
     journal = {Mathematische Annalen},
     pages = {113--123},
     publisher = {mathdoc},
     volume = {107},
     year = {1933},
     zbl = {0005.08301},
     url = {http://geodesic.mathdoc.fr/item/MAN_1933__107_159584/}
}