@misc{indiciaed3f48afb3b9b,
  title = {Geologic map of the Spruce Pine district, North Carolina},
  author = {John Lawrence Kulp and D.A. Brobst},
  year = {1953},
  doi = {10.3133/ofr53143},
  url = {https://pubs.usgs.gov/publication/ofr53143},
  note = {Source identifier: ofr53143}
}