@misc{indiciae8777851a8587,
  title = {Geologic map of the Saylorsburg quadrangle, Monroe and Northampton Counties, Pennsylvania},
  author = {Jack Burton Epstein},
  year = {1990},
  doi = {10.3133/gq1638},
  url = {https://pubs.usgs.gov/publication/gq1638},
  note = {Source identifier: gq1638}
}