@misc{indiciae1820e231603a,
  title = {Pitchblende deposits at the Wood and Calhoun mines, Central City mining district, Gilpin County, Colorado},
  author = {Frank R. Moore and C.R. Butler},
  year = {1952},
  doi = {10.3133/cir186},
  url = {https://pubs.usgs.gov/publication/cir186},
  note = {Source identifier: cir186}
}