@misc{indiciae64b572b69ffe,
  title = {Coal-A complex natural resource: An overview of factors affecting coal quality and use in the United States With a contribution on coal quality and public health},
  author = {Stanley P. Schweinfurth and Robert B. Finkelman},
  year = {2003},
  doi = {10.3133/cir1143},
  url = {https://pubs.usgs.gov/publication/cir1143},
  note = {Source identifier: cir1143}
}