@misc{indiciaeadc540a998ef,
  title = {Geology of the Corbin quadrangle, Kentucky},
  author = {Willard P. Puffett},
  year = {1963},
  doi = {10.3133/gq231},
  url = {https://pubs.usgs.gov/publication/gq231},
  note = {Source identifier: gq231}
}