@article{IM_1987__90_143504,
     author = {F. Kirwan},
     title = {Rational intersection cohomology of quotient varieties. {II.}},
     journal = {Inventiones mathematicae},
     pages = {153--168},
     publisher = {mathdoc},
     volume = {90},
     year = {1987},
     zbl = {0631.14012},
     url = {http://geodesic.mathdoc.fr/item/IM_1987__90_143504/}
}