TY  - RPRT
TI  - Estimating usable resources from historical industry data
AU  - S.M. Cargill
AU  - D. H. Root
AU  - E. H. Bailey
PY  - 1981
DO  - 10.2113/gsecongeo.76.5.1081
UR  - https://pubs.usgs.gov/publication/70207147
ID  - 70207147
ER  -