@misc{indiciaefedca1560669,
  title = {Geologic map of the southern part of the Slim Buttes area, Harding County, South Dakota},
  author = {George William Moore and James R. Gill},
  year = {1955},
  doi = {10.3133/coal36},
  url = {https://pubs.usgs.gov/publication/coal36},
  note = {Source identifier: coal36}
}