@misc{indiciaed4b6d6f4a015,
  title = {Exploration of the Jefren gypsum-anhydrite deposit, Tripolitania, Libya},
  author = {James Louis Gualtieri},
  year = {1962},
  doi = {10.3133/ofr6257},
  url = {https://pubs.usgs.gov/publication/ofr6257},
  note = {Source identifier: ofr6257}
}