@misc{indiciae011113ecbbf3,
  title = {A Matrix Knot Invariant.},
  author = {J W Alexander},
  year = {1933},
  doi = {10.1073/pnas.19.2.272},
  url = {https://pubmed.ncbi.nlm.nih.gov/16587770/},
  note = {Source identifier: 16587770}
}