@misc{indiciae14721dade2c0,
  title = {Mineral resources of the United States, 1919: Part II - Nonmetals},
  author = {Gerald Francis Loughlin and Ralph Walter Stone},
  year = {1922},
  doi = {10.3133/70175829},
  url = {https://pubs.usgs.gov/publication/70175829},
  note = {Source identifier: 70175829}
}