@article{MZ_1987__196_173898,
     author = {Morton E. Harris},
     title = {Filtrations, {Stable} {Clifford} {Theory} and {Group-Graded} {Rings} and {Modules.}},
     journal = {Mathematische Zeitschrift},
     pages = {497--510},
     publisher = {mathdoc},
     volume = {196},
     year = {1987},
     zbl = {0638.20003},
     url = {http://geodesic.mathdoc.fr/item/MZ_1987__196_173898/}
}