@misc{indiciae93cfdd6c1ae3,
  title = {Geology of the Flint Hill Quadrangle, Fall River County, South Dakota},
  author = {Henry Bell and Edwin Van Horn Post},
  year = {1971},
  doi = {10.3133/b1063m},
  url = {https://pubs.usgs.gov/publication/b1063M},
  note = {Source identifier: b1063M}
}