@misc{indiciaeb3ed9704a29a,
  title = {Sulphur and pyrite},
  author = {Frank L. Hess and Donnel Foster Hewett and Esper Signius Larsen and J. F. Hunter},
  year = {1913},
  doi = {10.3133/b530h},
  url = {https://pubs.usgs.gov/publication/b530H},
  note = {Source identifier: b530H}
}