@misc{indiciaed875b05c253f,
  title = {Coal resources of selected coal beds and zones in the Northern and Central Appalachian Basin},
  author = {Leslie F. Ruppert and Susan Tewalt and Linda Bragg},
  year = {2002},
  doi = {10.3133/fs00402},
  url = {https://pubs.usgs.gov/publication/fs00402},
  note = {Source identifier: fs00402}
}