@misc{indiciae3effaee18b64,
  title = {Mineral commodity profiles: Silver},
  author = {W. C. Butterman and Henry E. Hilliard},
  year = {2005},
  doi = {10.3133/ofr20041251},
  url = {https://pubs.usgs.gov/publication/ofr20041251},
  note = {Source identifier: ofr20041251}
}