@misc{indiciae493b31b58383,
  title = {Geologic map of the Broad Bottom quadrangle, eastern Kentucky},
  author = {Donald Clayton Alvord},
  year = {1965},
  doi = {10.3133/gq442},
  url = {https://pubs.usgs.gov/publication/gq442},
  note = {Source identifier: gq442}
}