@misc{indiciaed30540ab5290,
  title = {Geologic map of the Soldier quadrangle, northeastern Kentucky},
  author = {John Calvin Philley and David Kent Hylbert and Harry P. Hoge},
  year = {1975},
  doi = {10.3133/gq1233},
  url = {https://pubs.usgs.gov/publication/gq1233},
  note = {Source identifier: gq1233}
}