@misc{indiciae18ad5fecc2c1,
  title = {Geologic map of the Willard quadrangle, eastern Kentucky},
  author = {William Randall Brown},
  year = {1977},
  doi = {10.3133/gq1387},
  url = {https://pubs.usgs.gov/publication/gq1387},
  note = {Source identifier: gq1387}
}