@misc{indiciaefdfd26780168,
  title = {Geology of the Tygarts Valley quadrangle, Kentucky},
  author = {Richard A. Sheppard},
  year = {1964},
  doi = {10.3133/gq289},
  url = {https://pubs.usgs.gov/publication/gq289},
  note = {Source identifier: gq289}
}