@article{IM_1987__89_143488,
     author = {S. Kumar},
     title = {Demazure character formula in arbitrary {Kac-Moody} setting.},
     journal = {Inventiones mathematicae},
     pages = {395--424},
     publisher = {mathdoc},
     volume = {89},
     year = {1987},
     zbl = {0635.14023},
     url = {http://geodesic.mathdoc.fr/item/IM_1987__89_143488/}
}