@misc{indiciaee84df2c9e2e5,
  title = {Copper: a metal for the ages},
  author = {Jeff Doebrich},
  year = {2009},
  doi = {10.3133/fs20093031},
  url = {https://pubs.usgs.gov/publication/fs20093031},
  note = {Source identifier: fs20093031}
}