@misc{indiciaed2327b129e1a,
  title = {Pompeiu's problem on discrete space.},
  author = {D Zeilberger},
  year = {1978},
  doi = {10.1073/pnas.75.8.3555},
  url = {https://pubmed.ncbi.nlm.nih.gov/16592549/},
  note = {Source identifier: 16592549}
}