@misc{indiciae61575a61fa52,
  title = {Reconnaissance geologic map of the northern half of the Helmville Quadrangle, Powell County, Montana},
  author = {W. Mark Weber and Irving Jerome Witkind},
  year = {1979},
  doi = {10.3133/ofr79444},
  url = {https://pubs.usgs.gov/publication/ofr79444},
  note = {Source identifier: ofr79444}
}