@misc{indiciae91973ce7764a,
  title = {Geologic map of the Ezel quadrangle, Morgan and Menifee Counties, Kentucky},
  author = {G. N. Pipiringos and S.C. Bergman and Virgil A. Trent},
  year = {1968},
  doi = {10.3133/gq721},
  url = {https://pubs.usgs.gov/publication/gq721},
  note = {Source identifier: gq721}
}