@misc{indiciae8d329e0b5723,
  title = {The chemical analysis of Argonne Premium Coal samples},
  author = {Curtis A. Palmer and Frank G. Walthall},
  year = {1991},
  doi = {10.3133/ofr91638},
  url = {https://pubs.usgs.gov/publication/ofr91638},
  note = {Source identifier: ofr91638}
}