@misc{indiciae1f5d302a8431,
  title = {Geologic map of the Crofton quadrangle, Christian and Hopkins Counties, Kentucky},
  author = {Thomas M. Kehn},
  year = {1977},
  doi = {10.3133/gq1361},
  url = {https://pubs.usgs.gov/publication/gq1361},
  note = {Source identifier: gq1361}
}