@misc{indiciaeafeca8ce4a9d,
  title = {Altered wallrocks in the central part of the Front Range mineral belt, Gilpin and Clear Creek Counties, Colorado},
  author = {Edwin Wilson Tooker},
  year = {1963},
  doi = {10.3133/pp439},
  url = {https://pubs.usgs.gov/publication/pp439},
  note = {Source identifier: pp439}
}