@misc{indiciae3486e5063aaa,
  title = {Progress report on investigations of western phosphate deposits},
  author = {Roger Warren Swanson and Vincent Ellis McKelvey and Richard Porter Sheldon},
  year = {1953},
  doi = {10.3133/cir297},
  url = {https://pubs.usgs.gov/publication/cir297},
  note = {Source identifier: cir297}
}