@misc{indiciaecb0ac7df6bc5,
  title = {Geologic map of the Saint Charles quadrangle, Hopkins and Christian Counties, Kentucky},
  author = {James Edward Palmer},
  year = {1967},
  doi = {10.3133/gq674},
  url = {https://pubs.usgs.gov/publication/gq674},
  note = {Source identifier: gq674}
}