TY  - RPRT
TI  - Potentially hazardous elements in coal: Modes of occurrence and summary of concentration data for coal components
AU  - Allan Kolker
AU  - Robert B. Finkelman
PY  - 1998
DO  - 10.1080/07349349808945578
UR  - https://pubs.usgs.gov/publication/70020419
ID  - 70020419
ER  -