@misc{indiciae078131131527,
  title = {Porphyry copper deposit density},
  author = {Donald A. Singer and Vladimir Berger and W. David Menzie and Byron R. Berger},
  year = {2005},
  doi = {10.2113/gsecongeo.100.3.491},
  url = {https://pubs.usgs.gov/publication/70197200},
  note = {Source identifier: 70197200}
}