@misc{indiciaee24b8b4f37a4,
  title = {Preliminary map of coal strip mine areas in the conterminous United States},
  author = {Jack Burton Epstein},
  year = {1980},
  doi = {10.3133/ofr80926},
  url = {https://pubs.usgs.gov/publication/ofr80926},
  note = {Source identifier: ofr80926}
}