@misc{indiciaee362067c1fdb,
  title = {Geologic map and sections of parts of the Portland and Belvidere quadrangles, New Jersey-Pennsylvania},
  author = {Avery A. Drake and J. B. Epstein and J.M. Aaron},
  year = {1969},
  doi = {10.3133/i552},
  url = {https://pubs.usgs.gov/publication/i552},
  note = {Source identifier: i552}
}