@misc{indiciae3fedc2c139d8,
  title = {Geologic map of the Richardson Quadrangle, Lawrence and Johnson counties, Kentucky},
  author = {J. D. Sanchez and D.C. Alvord and Philip Thayer Hayes},
  year = {1977},
  doi = {10.3133/ofr77880},
  url = {https://pubs.usgs.gov/publication/ofr77880},
  note = {Source identifier: ofr77880}
}