@misc{indiciaeb1de36e1a4d5,
  title = {Geologic map of the Walton quadrangle, north-central Kentucky},
  author = {Stanley J. Luft},
  year = {1973},
  doi = {10.3133/gq1080},
  url = {https://pubs.usgs.gov/publication/gq1080},
  note = {Source identifier: gq1080}
}