@misc{indiciaeebeddaf36f21,
  title = {Reconnaissance evaluation of Pakistan for phosphate rock},
  author = {Richard Porter Sheldon},
  year = {1973},
  doi = {10.3133/ofr73260},
  url = {https://pubs.usgs.gov/publication/ofr73260},
  note = {Source identifier: ofr73260}
}