@misc{indiciaeafad654523f4,
  title = {Silver concentrations and selected hydrologic data in the Upper Colorado River basin, 1991-92},
  author = {D. A. Johncox},
  year = {1993},
  doi = {10.3133/ofr93447},
  url = {https://pubs.usgs.gov/publication/ofr93447},
  note = {Source identifier: ofr93447}
}