@misc{indiciae7dd591f96e12,
  title = {Geologic map of the Slim Buttes area, Harding County, South Dakota},
  author = {N.M. Denson and George Odell Bachman and H. D. Zeller},
  year = {1955},
  doi = {10.3133/coal35},
  url = {https://pubs.usgs.gov/publication/coal35},
  note = {Source identifier: coal35}
}