@misc{indiciae55a8cf3bf091,
  title = {Geologic map of the Horton quadrangle, Ohio County, Kentucky},
  author = {William D. Johnson},
  year = {1971},
  doi = {10.3133/gq915},
  url = {https://pubs.usgs.gov/publication/gq915},
  note = {Source identifier: gq915}
}