@misc{indiciaebd7c9166bd25,
  title = {Geologic map of the Powder River Basin and surrounding area, Wyoming, Montana, South Dakota, North Dakota, and Nebraska},
  author = {M.S. Ellis},
  year = {1989},
  doi = {10.3133/mf2095},
  url = {https://pubs.usgs.gov/publication/mf2095},
  note = {Source identifier: mf2095}
}