@article{MZ_1974__137_172059,
     author = {Manfred Wolff and G\"unter Mittelmeyer},
     title = {\"Uber den {Absolutbetrag} auf komplexen {Vektorverb\"anden.}},
     journal = {Mathematische Zeitschrift},
     pages = {87--92},
     publisher = {mathdoc},
     volume = {137},
     year = {1974},
     zbl = {0284.46010},
     url = {http://geodesic.mathdoc.fr/item/MZ_1974__137_172059/}
}