@misc{indiciae4a4af47b1ba2,
  title = {Stripping-coal resources of the United States},
  author = {Paul Averitt},
  year = {1968},
  doi = {10.3133/b1252c},
  url = {https://pubs.usgs.gov/publication/b1252C},
  note = {Source identifier: b1252C}
}