@misc{indiciae980dfd239db3,
  title = {The Pennsylvanian Fire Clay tonstein of the Appalachian basin—Its distribution, biostratigraphy, and mineralogy},
  author = {C. L. Rice and Harvey E. Belkin and T.W. Henry and R. E. Zartman and Michael J. Kunk},
  year = {1994},
  doi = {10.1130/spe294-p87},
  url = {https://pubs.usgs.gov/publication/70207647},
  note = {Source identifier: 70207647}
}