TY  - RPRT
TI  - Grade and tonnage model of Porphyry Cu deposits in British Columbia, Canada, and Alaska, U.S.A.
AU  - W. David Menzie
AU  - Donald A. Singer
PY  - 1993
DO  - 10.3133/ofr93275
UR  - https://pubs.usgs.gov/publication/ofr93275
ID  - ofr93275
ER  -