@article{MAN_1939__116_160028,
     author = {G. K\"othe},
     title = {Erweiterung von {Linearfunktionen} in linearen {R\"aumen}},
     journal = {Mathematische Annalen},
     pages = {719--732},
     year = {1939},
     volume = {116},
     zbl = {0021.32403},
     url = {http://geodesic.mathdoc.fr/item/MAN_1939__116_160028/}
}