@misc{indiciae06c759b49b21,
  title = {Preliminary coal map of the Cornettsville quadrangle, Perry, Knott, Letcher, Harlan, and Leslie Counties, Kentucky},
  author = {John Edward Johnston and Philip T. Stafford and Stewart W. Welch},
  year = {1955},
  doi = {10.3133/coal22},
  url = {https://pubs.usgs.gov/publication/coal22},
  note = {Source identifier: coal22}
}