@misc{indiciae7b0f25cfb231,
  title = {Geologic processes affecting the quality of the Upper Freeport coal bed, west-central Pennsylvania},
  author = {R.W. Stanton and C. B. Cecil and B.S. Pierce and L.F. Ruppert and F.T. Dulong},
  year = {1986},
  doi = {10.3133/ofr86173},
  url = {https://pubs.usgs.gov/publication/ofr86173},
  note = {Source identifier: ofr86173}
}