@misc{indiciae0da67de91efe,
  title = {Geologic map of the Perryville quadrangle, Mercer and Boyle Counties, Kentucky},
  author = {Earle Rupert Cressman},
  year = {1974},
  doi = {10.3133/gq1185},
  url = {https://pubs.usgs.gov/publication/gq1185},
  note = {Source identifier: gq1185}
}