@misc{indiciaecfc1362fa390,
  title = {Correlation chart for units on the geologic map of Kentucky},
  author = {R. C. McDowell},
  year = {1981},
  doi = {10.3133/mf1291},
  url = {https://pubs.usgs.gov/publication/mf1291},
  note = {Source identifier: mf1291}
}