@misc{indiciaeebdfc2e2bdf0,
  title = {Geologic map of Montana},
  author = {Clyde P. Ross and David A. Andrews and Irving J. Witkind},
  year = {1955},
  doi = {10.3133/70210885},
  url = {https://pubs.usgs.gov/publication/70210885},
  note = {Source identifier: 70210885}
}