@misc{indiciae3807047d7ee7,
  title = {Stripping-coal resources of the United States; January 1, 1970},
  author = {Paul Averitt},
  year = {1970},
  doi = {10.3133/b1322},
  url = {https://pubs.usgs.gov/publication/b1322},
  note = {Source identifier: b1322}
}