@misc{indiciae35641435ed1a,
  title = {Geologic map of the Riegelsville quadrangle, Pennsylvania-New Jersey},
  author = {Avery Ala Drake and Dean B. McLaughlin and Robert Ellis Davis},
  year = {1967},
  doi = {10.3133/gq593},
  url = {https://pubs.usgs.gov/publication/gq593},
  note = {Source identifier: gq593}
}