@misc{indiciae2b247e03424b,
  title = {Geologic map of the Salyersville South quadrangle, Magoffin and Breathitt Counties, Kentucky},
  author = {Richard W. Spengler},
  year = {1977},
  doi = {10.3133/gq1373},
  url = {https://pubs.usgs.gov/publication/gq1373},
  note = {Source identifier: gq1373}
}