@misc{indiciae62eeb765ce4f,
  title = {Geologic map of the Summitville mining district of Colorado},
  author = {T. A. Steven and J.C. MacLachlan},
  year = {1953},
  doi = {10.3133/ofr53250},
  url = {https://pubs.usgs.gov/publication/ofr53250},
  note = {Source identifier: ofr53250}
}