@misc{indiciaeed67dbf48cfe,
  title = {Lignite geology of the Keene area, McKenzie County, North Dakota},
  author = {John M. Spencer},
  year = {1981},
  doi = {10.3133/ofr81602},
  url = {https://pubs.usgs.gov/publication/ofr81602},
  note = {Source identifier: ofr81602}
}