@misc{indiciaeeec11f99bfa7,
  title = {Geologic map of the Sardis quadrangle, northeastern Kentucky},
  author = {Robert C. McDowell},
  year = {1973},
  doi = {10.3133/gq1091},
  url = {https://pubs.usgs.gov/publication/gq1091},
  note = {Source identifier: gq1091}
}