@misc{indiciae450320e8466f,
  title = {Gypsum and anhydrite in the United States},
  author = {Charles F. Withington},
  year = {1961},
  doi = {10.3133/ofr61174},
  url = {https://pubs.usgs.gov/publication/ofr61174},
  note = {Source identifier: ofr61174}
}