@misc{indiciae7d1931367aff,
  title = {Radiometric ages of intrusive rocks in the Little Belt Mountains, Montana},
  author = {Richard F. Marvin and Irving J. Witkind and William R. Keefer and Harald H. Mehnert},
  year = {1973},
  doi = {10.1130/0016-7606(1973)84<1977:raoiri>2.0.co;2},
  url = {https://pubs.usgs.gov/publication/70241489},
  note = {Source identifier: 70241489}
}