@misc{indiciae489aa894cf9a,
  title = {Preliminary geologic map of Pine Mountain in Harlan, Letcher, and Pike Counties, Kentucky},
  author = {A.J. Froelich and D.E. Wolcott and C. L. Rice and E. K. Maughan},
  year = {1970},
  doi = {10.3133/ofr70131},
  url = {https://pubs.usgs.gov/publication/ofr70131},
  note = {Source identifier: ofr70131}
}