@misc{indiciaeb4ba1bd436b9,
  title = {Aeromagnetic, Bouguer gravity, and generalized geologic maps of the central part of the Little Belt Mountains, Montana},
  author = {M. D. Kleinkopf and I. J. Witkind and W. R. Keefer},
  year = {1972},
  doi = {10.3133/gp837},
  url = {https://pubs.usgs.gov/publication/gp837},
  note = {Source identifier: gp837}
}