@misc{indiciae660560d7749d,
  title = {Geology of the McCalls Ferry-Quarryville district, Pennsylvania},
  author = {Eleanora Frances Bliss Knopf and Anna Isabel Jonas},
  year = {1929},
  doi = {10.3133/b799},
  url = {https://pubs.usgs.gov/publication/b799},
  note = {Source identifier: b799}
}