@misc{indiciaee20224f43405,
  title = {Transformations of Einstein Spaces.},
  author = {H P Robertson},
  year = {1925},
  doi = {10.1073/pnas.11.10.590},
  url = {https://pubmed.ncbi.nlm.nih.gov/16587042/},
  note = {Source identifier: 16587042}
}