TY  - RPRT
TI  - Calculation of coal resources using ARC/INFO and Earth Vision; methodology for the National Coal Resource Assessment
AU  - L.N. Roberts
AU  - L.R. Biewick
PY  - 1999
DO  - 10.3133/ofr995
UR  - https://pubs.usgs.gov/publication/ofr995
ID  - ofr995
ER  -