TY  - RPRT
TI  - The COALPROD database; historical production data for the major coal-producing regions of the conterminous United States
AU  - Robert C. Milici
PY  - 1997
DO  - 10.3133/ofr97447b
UR  - https://pubs.usgs.gov/publication/ofr97447B
ID  - ofr97447B
ER  -