@misc{indiciae597a8a5adeec,
  title = {The Shenango Formation (Mississippian) in northwestern Pennsylvania},
  author = {Grant E. Kimmel and George R. Schiner},
  year = {1970},
  doi = {10.3133/b1294c},
  url = {https://pubs.usgs.gov/publication/b1294C},
  note = {Source identifier: b1294C}
}