@article{MZ_1984__186_173437,
     author = {Peter F\"orster},
     title = {Projektive {Klassen} endlicher {Gruppen.} {I.} {Schunck-} und {Gasch\"utzklassen.}},
     journal = {Mathematische Zeitschrift},
     pages = {149--178},
     publisher = {mathdoc},
     volume = {186},
     year = {1984},
     zbl = {0544.20015},
     url = {http://geodesic.mathdoc.fr/item/MZ_1984__186_173437/}
}