@article{IM_1991__106_1_143946,
     author = {M. Van den Bergh},
     title = {Cohen-Macaulayness of modules of covariants.},
     journal = {Inventiones mathematicae},
     pages = {389--410},
     year = {1991},
     volume = {106},
     number = {1},
     zbl = {0761.13004},
     url = {http://geodesic.mathdoc.fr/item/IM_1991__106_1_143946/}
}