TY  - RPRT
TI  - Grade and Tonnage Relationships Among Copper Deposits
AU  - D.A. Singer
AU  - Dennis P. Cox
AU  - Lawrence J. Drew
PY  - 1975
DO  - 10.3133/pp907a
UR  - https://pubs.usgs.gov/publication/pp907A
ID  - pp907A
ER  -