@misc{indiciaee7e8c5956755,
  title = {Geology of the Pleasant Green Hill quadrangle, Kentucky},
  author = {Willis H. Nelson},
  year = {1964},
  doi = {10.3133/gq321},
  url = {https://pubs.usgs.gov/publication/gq321},
  note = {Source identifier: gq321}
}