@article{MAN_1928__100_159308,
     author = {H. Kneser},
     title = {Gl\"attung von {Fl\"achenabbildungen}},
     journal = {Mathematische Annalen},
     pages = {609--617},
     publisher = {mathdoc},
     volume = {100},
     year = {1928},
     language = {de},
     url = {http://geodesic.mathdoc.fr/item/MAN_1928__100_159308/}
}