@misc{indiciaec4cc6ddbae2b,
  title = {Geologic map of the Quality quadrangle, Butler and Logan Counties, Kentucky},
  author = {Benjamin Gildersleeve},
  year = {1968},
  doi = {10.3133/gq673},
  url = {https://pubs.usgs.gov/publication/gq673},
  note = {Source identifier: gq673}
}