@misc{indiciae76f351b2c509,
  title = {Geology of the Portsmouth quadrangle, Kentucky-Ohio, and parts of the Wheelersburg and New Boston quadrangles, Kentucky},
  author = {Richard A. Sheppard},
  year = {1964},
  doi = {10.3133/gq312},
  url = {https://pubs.usgs.gov/publication/gq312},
  note = {Source identifier: gq312}
}