@misc{indiciae4320fef84dec,
  title = {Potentially hazardous elements in coal: Modes of occurrence and summary of concentration data for coal components},
  author = {Allan Kolker and Robert B. Finkelman},
  year = {1998},
  doi = {10.1080/07349349808945578},
  url = {https://pubs.usgs.gov/publication/70020419},
  note = {Source identifier: 70020419}
}