@misc{indiciaeb993a3093070,
  title = {Geologic map and lignite deposits of the Glen Ullin Quadrangle, Morton County, North Dakota},
  author = {C.S.V. Barclay},
  year = {1973},
  doi = {10.3133/coal54},
  url = {https://pubs.usgs.gov/publication/coal54},
  note = {Source identifier: coal54}
}