@misc{indiciae07c90f130584,
  title = {Bedrock geologic map of the Allentown West quadrangle, Lehigh and Berks counties, Pennsylvania},
  author = {Avery Ala Drake},
  year = {1993},
  doi = {10.3133/gq1727},
  url = {https://pubs.usgs.gov/publication/gq1727},
  note = {Source identifier: gq1727}
}