@misc{indiciaed99fed3d829e,
  title = {Mineral resources of the United States, 1920: Part I - Metals},
  author = {Gerald Francis Loughlin},
  year = {1922},
  doi = {10.3133/70175843},
  url = {https://pubs.usgs.gov/publication/70175843},
  note = {Source identifier: 70175843}
}