@misc{indiciae0d180128150c,
  title = {Gold in porphyry copper systems},
  author = {Edwin Wilson Tooker and L. P. James and T. G. Theodore and S. S. Howe and D. W. Blake and D. R. Shawe and R. P. Ashley and L. M. H. Carter},
  year = {1990},
  doi = {10.3133/b1857e},
  url = {https://pubs.usgs.gov/publication/b1857E},
  note = {Source identifier: b1857E}
}