@article{MAN_1950__122_160208,
     author = {Wilhelm Maak},
     title = {Fastperiodische invariante {Vektormoduln} in einem metrischen {Vektorraum.}},
     journal = {Mathematische Annalen},
     pages = {157--166},
     publisher = {mathdoc},
     volume = {122},
     year = {1950},
     zbl = {0041.41407},
     url = {http://geodesic.mathdoc.fr/item/MAN_1950__122_160208/}
}