@misc{indiciae53b9b487f696,
  title = {Geologic map of the Tilford quadrangle, southeastern Kentucky},
  author = {Willard P. Puffett},
  year = {1965},
  doi = {10.3133/gq451},
  url = {https://pubs.usgs.gov/publication/gq451},
  note = {Source identifier: gq451}
}