@misc{indiciae815e8eb4f460,
  title = {Pyrophyllite and kyanite and related minerals in the United States},
  author = {Gilbert H. Espenshade},
  year = {1961},
  doi = {10.3133/ofr6146},
  url = {https://pubs.usgs.gov/publication/ofr6146},
  note = {Source identifier: ofr6146}
}