@misc{indiciaea6eade7d0e38,
  title = {Ore deposits in rocks of Paleozoic and Tertiary age of the northern Black Hills, South Dakota},
  author = {Lewis H. Shapiro and John Paul Gries},
  year = {1970},
  doi = {10.3133/ofr70300},
  url = {https://pubs.usgs.gov/publication/ofr70300},
  note = {Source identifier: ofr70300}
}