@misc{indiciae2220aac76ae5,
  title = {Geologic map of the Fort Knox quadrangle, north-central Kentucky},
  author = {Roy Clark Kepferle and Edward G. Sable},
  year = {1977},
  doi = {10.3133/gq1375},
  url = {https://pubs.usgs.gov/publication/gq1375},
  note = {Source identifier: gq1375}
}