@misc{indiciae154d014d9d2a,
  title = {Slate deposits and slate industry of the United States},
  author = {T. Nelson Dale and Edwin C. Eckel and W. F. Hillebrand and A. T. Coons},
  year = {1906},
  doi = {10.3133/b275},
  url = {https://pubs.usgs.gov/publication/b275},
  note = {Source identifier: b275}
}