@misc{indiciae159292469bd9,
  title = {U.S. Geological Survey resource assessment of selected Tertiary coal zones in Wyoming, Montana and North Dakota},
  author = {D. J. Nichols and M.S. Ellis},
  year = {2003},
  url = {https://pubs.usgs.gov/publication/70026126},
  note = {Source identifier: 70026126}
}