@misc{indiciaec1e8c220304b,
  title = {Mineral resources of the United States, 1922: Part II - Nonmetals},
  author = {Gerald Francis Loughlin and Frank James Katz},
  year = {1925},
  doi = {10.3133/70175848},
  url = {https://pubs.usgs.gov/publication/70175848},
  note = {Source identifier: 70175848}
}