@misc{indiciae01e85fa3ad51,
  title = {Geology of the Calamity Peak area, Custer County, South Dakota},
  author = {Donald H. Kupfer},
  year = {1954},
  doi = {10.3133/tei294},
  url = {https://pubs.usgs.gov/publication/tei294},
  note = {Source identifier: tei294}
}