@misc{indiciae41dfc9cc4a7d,
  title = {Preliminary report on the geology of the Senator mine area, Caldwell county, Kentucky},
  author = {W. R. Thurston and G. C. Hardin and R. D. Trace},
  year = {1943},
  doi = {10.3133/ofr437},
  url = {https://pubs.usgs.gov/publication/ofr437},
  note = {Source identifier: ofr437}
}