@article{MZ_1955__63_169546,
     author = {Rudolf Kochend\"orfer},
     title = {\"Uber den {Multiplikator} einer {Gruppe.}},
     journal = {Mathematische Zeitschrift},
     pages = {507--513},
     year = {1955},
     volume = {63},
     zbl = {0070.25602},
     url = {http://geodesic.mathdoc.fr/item/MZ_1955__63_169546/}
}