@misc{indiciae17400681942d,
  title = {ABSTRACT HOMOTOPY.},
  author = {D M Kan},
  year = {1955},
  doi = {10.1073/pnas.41.12.1092},
  url = {https://pubmed.ncbi.nlm.nih.gov/16589801/},
  note = {Source identifier: 16589801}
}