@misc{indiciaecf441b426eba,
  title = {Mineralogy of ash of some American coals: Variations with temperature and source},
  author = {R.S. Mitchell and H.J. Gluskoter},
  year = {1976},
  doi = {10.1016/0016-2361(76)90001-6},
  url = {https://pubs.usgs.gov/publication/70010933},
  note = {Source identifier: 70010933}
}