TY  - RPRT
TI  - Concentrations of platinum group elements in 122 U.S. coal samples
AU  - C.L. Oman
AU  - R. B. Finkelman
AU  - S.J. Tewalt
PY  - 1997
DO  - 10.3133/ofr9753
UR  - https://pubs.usgs.gov/publication/ofr9753
ID  - ofr9753
ER  -