@misc{indiciae1a2b612bd10a,
  title = {Evaluation of economically extractable coal resources in the Gillette coal field, Powder River basin, Wyoming},
  author = {Margaret S. Ellis and Carol L. Molnia and Lee M. Osmonson and Allan M. Ochs and Timothy J. Rohrbacher and Tracy J. Mercier and Laura N.R. Roberts},
  year = {2002},
  doi = {10.3133/ofr02180},
  url = {https://pubs.usgs.gov/publication/ofr02180},
  note = {Source identifier: ofr02180}
}