@misc{indiciaeb68022e7cc07,
  title = {Geologic map of the west half of the Neihart 15-minute Quadrangle, central Montana},
  author = {W. R. Keefer},
  year = {1972},
  doi = {10.3133/i726},
  url = {https://pubs.usgs.gov/publication/i726},
  note = {Source identifier: i726}
}