@article{MZ_1994__216_4_174638,
     author = {Edgar M\"uller and Otto Mutzbauer},
     title = {Das {Gewicht} einer {Butlergruppe.}},
     journal = {Mathematische Zeitschrift},
     pages = {69--82},
     publisher = {mathdoc},
     volume = {216},
     number = {4},
     year = {1994},
     language = {de},
     url = {http://geodesic.mathdoc.fr/item/MZ_1994__216_4_174638/}
}