@misc{indiciae0921bc311198,
  title = {Geology of the Spruce Pine district, Avery, Mitchell, and Yancey Counties, North Carolina},
  author = {Donald Albert Brobst},
  year = {1962},
  doi = {10.3133/b1122a},
  url = {https://pubs.usgs.gov/publication/b1122A},
  note = {Source identifier: b1122A}
}