@article{JRAM_1993__438_153517,
     author = {Nicholas M. Katz},
     title = {Estimates for {Soto-Andrade} sums.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {143--162},
     publisher = {mathdoc},
     volume = {438},
     year = {1993},
     zbl = {0798.11053},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1993__438_153517/}
}