@misc{indiciae76201f266c2a,
  title = {Geologic map of the Wagon Wheel Gap fluorspar district, Colorado},
  author = {T. A. Steven},
  year = {1968},
  doi = {10.3133/ofr68259},
  url = {https://pubs.usgs.gov/publication/ofr68259},
  note = {Source identifier: ofr68259}
}