@misc{indiciae1cfb0d23af7a,
  title = {The Valley and Ridge Province of eastern Pennsylvania - Stratigraphic and sedimentologic contributions and problems},
  author = {Jack B. Epstein},
  year = {2006},
  doi = {10.1002/gj.3350210306},
  url = {https://pubs.usgs.gov/publication/70014574},
  note = {Source identifier: 70014574}
}