@misc{indiciae19c7402687b9,
  title = {Geology of the Ellsworth quadrangle, Pennsylvania},
  author = {Henry L. Berryhill and Stanley P. Schweinfurth},
  year = {1964},
  doi = {10.3133/gq333},
  url = {https://pubs.usgs.gov/publication/gq333},
  note = {Source identifier: gq333}
}