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/ofr97447a
UR  - https://pubs.usgs.gov/publication/ofr97447A
ID  - ofr97447A
ER  -