@misc{indiciae6edab7e7c904,
  title = {Geologic maps of Crystal graphite mine, Beaverhead County, Montana},
  author = {Frank C. Armstrong and Roy P. Full},
  year = {1950},
  doi = {10.3133/ofr5026},
  url = {https://pubs.usgs.gov/publication/ofr5026},
  note = {Source identifier: ofr5026}
}