@article{MZ_1987__196_173876,
     author = {Friedrich Knop and Peter Littelmann},
     title = {Der {Grad} erzeugender {Funktionen} von {Invariantenringen.}},
     journal = {Mathematische Zeitschrift},
     pages = {211--230},
     publisher = {mathdoc},
     volume = {196},
     year = {1987},
     zbl = {0635.20017},
     url = {http://geodesic.mathdoc.fr/item/MZ_1987__196_173876/}
}