@misc{indiciaecbd57b5cb8ec,
  title = {Geology of the Wood and East Calhoun mines, Central City district, Gilpin County, Colorado},
  author = {Avery Drake},
  year = {1957},
  doi = {10.3133/b1032c},
  url = {https://pubs.usgs.gov/publication/b1032C},
  note = {Source identifier: b1032C}
}