@misc{indiciae60ab9f0f33e6,
  title = {Geologic map of the Smithfield quadrangle, north-central Kentucky},
  author = {Stanley J. Luft},
  year = {1977},
  doi = {10.3133/gq1371},
  url = {https://pubs.usgs.gov/publication/gq1371},
  note = {Source identifier: gq1371}
}