@misc{indiciae8093ddfd5fc0,
  title = {Assessment of undiscovered porphyry copper deposits within the range of the northern spotted owl, northwestern California, western Oregon, and western Washington},
  author = {Michael F. Diggles},
  year = {1991},
  doi = {10.3133/ofr91377},
  url = {https://pubs.usgs.gov/publication/ofr91377},
  note = {Source identifier: ofr91377}
}