@misc{indiciae147251a859f5,
  title = {Abstract Flat Projective Geometry.},
  author = {A D Michal and A B Mewborn},
  year = {1939},
  doi = {10.1073/pnas.25.8.440},
  url = {https://pubmed.ncbi.nlm.nih.gov/16577932/},
  note = {Source identifier: 16577932}
}