@misc{indiciae0666a9c60489,
  title = {Preliminary geologic map of the Chalky Buttes area, Slope County, North Dakota},
  author = {George William Moore and Robert E. Melin and Roy Clark Kepferle},
  year = {1956},
  doi = {10.3133/coal38},
  url = {https://pubs.usgs.gov/publication/coal38},
  note = {Source identifier: coal38}
}