@misc{indiciae2ab597ab7f42,
  title = {Mineral resources of the United States, 1916: Part II - Nonmetals},
  author = {Hiram Dryer McCaskey and Ernest Francis Burchard and Gerald Francis Loughlin},
  year = {1919},
  doi = {10.3133/70175818},
  url = {https://pubs.usgs.gov/publication/70175818},
  note = {Source identifier: 70175818}
}