TY  - RPRT
TI  - Estimate of undiscovered copper resources of the world, 2013
AU  - Kathleen M. Johnson
AU  - Jane M. Hammarstrom
AU  - Michael L. Zientek
AU  - Connie L. Dicken
PY  - 2014
DO  - 10.3133/fs20143004
UR  - https://pubs.usgs.gov/publication/fs20143004
ID  - fs20143004
ER  -