@misc{indiciaea29a4d3494ce,
  title = {USGS Permo-Carboniferous fossil locality register; Part 1, Introduction to PC-FILES},
  author = {T. W. Henry and O.B. Williams and P.A. Holroyd},
  year = {1993},
  doi = {10.3133/ofr93513},
  url = {https://pubs.usgs.gov/publication/ofr93513},
  note = {Source identifier: ofr93513}
}