@misc{indiciaebf1af9894eee,
  title = {Revised correlation chart of coal beds, coal zones, and key stratigraphic units in the Pennsylvanian rocks of eastern Kentucky},
  author = {Charles L. Rice and John K. Hiett},
  year = {1994},
  doi = {10.3133/mf2275},
  url = {https://pubs.usgs.gov/publication/mf2275},
  note = {Source identifier: mf2275}
}