@misc{indiciae979531c38007,
  title = {Generalized Homology Groups.},
  author = {W Mayer and A D Campbell},
  year = {1940},
  doi = {10.1073/pnas.26.11.655},
  url = {https://pubmed.ncbi.nlm.nih.gov/16577990/},
  note = {Source identifier: 16577990}
}