@misc{indiciaed069cfa968bc,
  title = {Coal fields of the conterminous United States—National Coal Resource Assessment updated version},
  author = {Joseph A. East},
  year = {2013},
  doi = {10.3133/ofr20121205},
  url = {https://pubs.usgs.gov/publication/ofr20121205},
  note = {Source identifier: ofr20121205}
}