@misc{indiciae57a9d23a3a03,
  title = {Iron Hill area, Carbonate mining district, Lawrence County, South Dakota},
  author = {J.P. Gries and Thomas Kiesling},
  year = {1969},
  doi = {10.3133/ofr69109},
  url = {https://pubs.usgs.gov/publication/ofr69109},
  note = {Source identifier: ofr69109}
}