@misc{indiciaea4140e00014c,
  title = {DUALITY RELATIONS IN TOPOLOGY.},
  author = {S Lefschetz},
  year = {1929},
  doi = {10.1073/pnas.15.4.367},
  url = {https://pubmed.ncbi.nlm.nih.gov/16587484/},
  note = {Source identifier: 16587484}
}