@misc{indiciaecd0a001814e3,
  title = {Geologic and structure map of a cryptoexplosion structure near Versailles, Kentucky},
  author = {Douglas F. B. Black},
  year = {1963},
  doi = {10.3133/ofr639},
  url = {https://pubs.usgs.gov/publication/ofr639},
  note = {Source identifier: ofr639}
}