@misc{indiciaeccf05c2fa3a2,
  title = {The electrum-tarnish method for the determination of the fugacity of sulfur in laboratory sulfide systems},
  author = {P. B. Barton and P. Toulmin},
  year = {1964},
  doi = {10.1016/0016-7037(64)90082-1},
  url = {https://pubs.usgs.gov/publication/70010549},
  note = {Source identifier: 70010549}
}