@misc{indiciae790830fdec2c,
  title = {Geologic map of the Butler quadrangle, Pendleton and Campbell Counties, Kentucky},
  author = {Stanley J. Luft},
  year = {1972},
  doi = {10.3133/gq982},
  url = {https://pubs.usgs.gov/publication/gq982},
  note = {Source identifier: gq982}
}