@misc{indiciaefc571c085c6a,
  title = {Postulates for an Abstract Arithmetic.},
  author = {M Ward},
  year = {1928},
  doi = {10.1073/pnas.14.12.907},
  url = {https://pubmed.ncbi.nlm.nih.gov/16587421/},
  note = {Source identifier: 16587421}
}