@article{JRAM_1970__245_151070,
     author = {Clifton Whyburn},
     title = {The distribution of r-th powers in a finite field.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {183--187},
     publisher = {mathdoc},
     volume = {245},
     year = {1970},
     zbl = {0205.35504},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1970__245_151070/}
}