@misc{indiciae4fd0412acba7,
  title = {Selected references: Coal geology of the central and southern Appalachian basin},
  author = {Leslie F. Ruppert and Susan J. Tewalt and Yomayra A. Roman Colon},
  year = {2014},
  doi = {10.3133/pp1708h.3},
  url = {https://pubs.usgs.gov/publication/pp1708H.3},
  note = {Source identifier: pp1708H.3}
}