@article{GraeterWirths2015,
  author    = {Joachim Gr{\"a}ter and Karl-Joachim Wirths},
  title     = {On Elementary Bounds for Sigma(infinity)(k=n)k(-s)},
  journal   = {The American mathematical monthly : an official publication of the Mathematical Association of America},
  volume    = {122},
  number    = {2},
  pages     = {155 -- 158},
  doi       = {10.4169/amer.math.monthly.122.02.155},
  year      = {2015},
}