@article{KellerPinchoverPogorzelski2018,
  author    = {Matthias Keller and Yehuda Pinchover and Felix Pogorzelski},
  title     = {An improved discrete hardy inequality},
  journal   = {The American mathematical monthly : an official publication of the Mathematical Association of America},
  volume    = {125},
  number    = {4},
  pages     = {347 -- 350},
  doi       = {10.1080/00029890.2018.1420995},
  year      = {2018},
}