@misc{indiciae29b72eceabef,
  title = {Database of significant deposits of gold, silver, copper, lead, and zinc in the United States},
  author = {Keith R. Long and DeYoung and Stephen Ludington},
  year = {1998},
  doi = {10.3133/ofr98206ab},
  url = {https://pubs.usgs.gov/publication/ofr98206AB},
  note = {Source identifier: ofr98206AB}
}