@misc{indiciae0b76127b1ba9,
  title = {Geologic map of parts of the Plains and Perma quadrangles, western Montana},
  author = {Earle Rupert Cressman},
  year = {1981},
  doi = {10.3133/ofr81785},
  url = {https://pubs.usgs.gov/publication/ofr81785},
  note = {Source identifier: ofr81785}
}