@misc{indiciae9a087db0587c,
  title = {Geology of anthracite in the eastern part of the Shenandoah quadrangle, Pennsylvania},
  author = {Thomas M. Kehn and Holly Clyde Wagner},
  year = {1955},
  doi = {10.3133/coal19},
  url = {https://pubs.usgs.gov/publication/coal19},
  note = {Source identifier: coal19}
}