@misc{indiciae5413cfe50827,
  title = {Mineral commodity summaries 2021},
  author = {U.S. Geological Survey},
  year = {2021},
  doi = {10.3133/mcs2021},
  url = {https://pubs.usgs.gov/publication/mcs2021},
  note = {Source identifier: mcs2021}
}