@misc{indiciae28071d727ac7,
  title = {Geology of the Paonia coal field, Delta and Gunnison Counties, Colorado},
  author = {V. H. Johnson and D. A. Andrews and R.C. Robeck},
  year = {1948},
  doi = {10.3133/ofr486},
  url = {https://pubs.usgs.gov/publication/ofr486},
  note = {Source identifier: ofr486}
}