@article{JOLT_2020_30_4_a11,
     author = {Joergen Ellegaard Andersen and Jens Carsten Jantzen and Du Pei},
     title = {Identities for {Poincar\'e} {Polynomials} via {Kostant} {Cascades}},
     journal = {Journal of Lie Theory},
     pages = {1131--1160},
     year = {2020},
     volume = {30},
     number = {4},
     url = {http://geodesic.mathdoc.fr/item/JOLT_2020_30_4_a11/}
}