@article{IM_1985__81_143271,
     author = {Claudio Procesi and Gerald Schwarz},
     title = {Inequalities defining orbit spaces.},
     journal = {Inventiones mathematicae},
     pages = {539--554},
     year = {1985},
     volume = {81},
     zbl = {0578.14010},
     url = {http://geodesic.mathdoc.fr/item/IM_1985__81_143271/}
}