@misc{indiciaedc52bdb45eac,
  title = {Gypsum and anhydrite in the United States, exclusive of Alaska and Hawaii},
  author = {Charles F. Withington},
  year = {1962},
  doi = {10.3133/mr33},
  url = {https://pubs.usgs.gov/publication/mr33},
  note = {Source identifier: mr33}
}