@misc{indiciae8b53bb9d5044,
  title = {Preliminary data on some Precambrian deposits of zinc-copper-lead sulfides and zinc spinel (granite) in Colorado},
  author = {Douglas M. Sheridan and William H. Raymond},
  year = {1977},
  doi = {10.3133/ofr77607},
  url = {https://pubs.usgs.gov/publication/ofr77607},
  note = {Source identifier: ofr77607}
}