@article{MAN_1920__81_158826,
     author = {H. Beck},
     title = {\"Uber lineare {Somenmannigfaltigkeiten}},
     journal = {Mathematische Annalen},
     pages = {187--218},
     publisher = {mathdoc},
     volume = {81},
     year = {1920},
     zbl = {47.0579.03},
     url = {http://geodesic.mathdoc.fr/item/MAN_1920__81_158826/}
}