@article{IM_1990__101_2_143798,
     author = {Alan Adolphson and Steven Sperber},
     title = {Exponential sums on {(Gm)n.}},
     journal = {Inventiones mathematicae},
     pages = {63--80},
     publisher = {mathdoc},
     volume = {101},
     number = {2},
     year = {1990},
     zbl = {0764.11037},
     url = {http://geodesic.mathdoc.fr/item/IM_1990__101_2_143798/}
}