@misc{indiciae1157e7f39a37,
  title = {Geologic map of the Blacks Ferry quadrangle, Monroe and Cumberland Counties, Kentucky},
  author = {Richard Van Horn},
  year = {1969},
  doi = {10.3133/gq803},
  url = {https://pubs.usgs.gov/publication/gq803},
  note = {Source identifier: gq803}
}