@misc{indiciae16da3ba344b1,
  title = {Coal resource occurrence and coal development potential maps of the Sonnette quadrangle, Powder River County, Montana},
  author = {Colorado School of Mines},
  year = {1979},
  doi = {10.3133/ofr7998},
  url = {https://pubs.usgs.gov/publication/ofr7998},
  note = {Source identifier: ofr7998}
}