@misc{indiciae4751f5ba3efc,
  title = {Geologic map of the Higginsport quadrangle, Ohio-Kentucky, and part of the Russellville quadrangle, Mason County, Kentucky},
  author = {William F. Outerbridge and Malcolm P. Weiss and Robert H. Osborne},
  year = {1973},
  doi = {10.3133/gq1065},
  url = {https://pubs.usgs.gov/publication/gq1065},
  note = {Source identifier: gq1065}
}