@misc{indiciae4f4fb404bdc8,
  title = {Preliminary report on rank of deep coals in part of the southern Piceance Creek basin, Colorado},
  author = {Val L. Freeman},
  year = {1979},
  doi = {10.3133/ofr79725},
  url = {https://pubs.usgs.gov/publication/ofr79725},
  note = {Source identifier: ofr79725}
}