@misc{indiciaef56fc50035bd,
  title = {Copper},
  author = {Sidney Paige and W. H. Emmons and F.B. Laney},
  year = {1911},
  doi = {10.3133/b470c},
  url = {https://pubs.usgs.gov/publication/b470C},
  note = {Source identifier: b470C}
}