@article{IM_1996__123_3_144357,
     author = {Shrawan Kumar},
     title = {The nil {Hecke} ring and singularity of {Schubert} varieties.},
     journal = {Inventiones mathematicae},
     pages = {471--506},
     publisher = {mathdoc},
     volume = {123},
     number = {3},
     year = {1996},
     zbl = {0863.14031},
     url = {http://geodesic.mathdoc.fr/item/IM_1996__123_3_144357/}
}