@misc{indiciae6a0159b22980,
  title = {Map of structural features in part of central Kentucky},
  author = {Douglas F. B. Black},
  year = {1970},
  doi = {10.3133/ofr7028},
  url = {https://pubs.usgs.gov/publication/ofr7028},
  note = {Source identifier: ofr7028}
}