@misc{indiciae0427e684cae3,
  title = {Geologic map of the Mill Springs quadrangle, south-central Kentucky},
  author = {Richard Quintin Lewis},
  year = {1972},
  doi = {10.3133/gq1057},
  url = {https://pubs.usgs.gov/publication/gq1057},
  note = {Source identifier: gq1057}
}