@misc{indiciae5c257894540f,
  title = {Geologic maps of parts of the Naugatuck and Delbarton quadrangles, eastern Kentucky},
  author = {Donald Clayton Alvord},
  year = {1971},
  doi = {10.3133/gq879},
  url = {https://pubs.usgs.gov/publication/gq879},
  note = {Source identifier: gq879}
}