@misc{indiciae99023af26905,
  title = {A marker algebra.},
  author = {J H Edwards},
  year = {1972},
  doi = {10.1111/j.1399-0004.1972.tb01470.x},
  url = {https://pubmed.ncbi.nlm.nih.gov/5084383/},
  note = {Source identifier: 5084383}
}