TY  - RPRT
TI  - Modes of occurrence of potentially hazardous elements in coal: Levels of confidence
AU  - Robert B. Finkelman
PY  - 1994
DO  - 10.1016/0378-3820(94)90169-4
UR  - https://pubs.usgs.gov/publication/70017616
ID  - 70017616
ER  -