@misc{indiciaef81df15bf9af,
  title = {Geologic map of the Marion quadrangle, Crittenden and Caldwell Counties, Kentucky},
  author = {Robert Denny Trace},
  year = {1966},
  doi = {10.3133/gq547},
  url = {https://pubs.usgs.gov/publication/gq547},
  note = {Source identifier: gq547}
}