@article{CMH_1931__3_138562,
     author = {H. Hopf and W. Rinow},
     title = {Ueber den {Begriff} der vollst\"andigen differentialgeometrischen {Fl\"ache.}},
     journal = {Commentarii mathematici Helvetici},
     pages = {209--225},
     publisher = {mathdoc},
     volume = {3},
     year = {1931},
     zbl = {0002.35004},
     url = {http://geodesic.mathdoc.fr/item/CMH_1931__3_138562/}
}