@misc{indiciae86d30357b2a7,
  title = {Formalism for Conformal Geometry.},
  author = {O Veblen},
  year = {1935},
  doi = {10.1073/pnas.21.3.168},
  url = {https://pubmed.ncbi.nlm.nih.gov/16587953/},
  note = {Source identifier: 16587953}
}