@misc{indiciae66a8a1a991c0,
  title = {Estimated resources of non-leased federal coal, Powder River Basin, Montana and Wyoming},
  author = {V. A. Trent},
  year = {1986},
  doi = {10.3133/mf1887},
  url = {https://pubs.usgs.gov/publication/mf1887},
  note = {Source identifier: mf1887}
}