@misc{indiciae8b3bddba5d10,
  title = {Coal resources of Beaver County, Pennsylvania},
  author = {E. D. Patterson},
  year = {1963},
  doi = {10.3133/b1143a},
  url = {https://pubs.usgs.gov/publication/b1143A},
  note = {Source identifier: b1143A}
}