@misc{indiciae224f9797622d,
  title = {Coals in the area between Bon Air and Clifty, Tennessee},
  author = {Charles Butts},
  year = {1917},
  doi = {10.3133/b641k},
  url = {https://pubs.usgs.gov/publication/b641K},
  note = {Source identifier: b641K}
}