@misc{indiciaea09b9bfeaa0f,
  title = {Geologic map and coal resources of the White Butte West quadrangle, Hettinger County, North Dakota},
  author = {Kenneth S. Soward},
  year = {1975},
  doi = {10.3133/coal69},
  url = {https://pubs.usgs.gov/publication/coal69},
  note = {Source identifier: coal69}
}