TY  - BOOK
T1  - Porphyry gold :a supplement to U.S. Geological Survey bulletin 1693 /
DA  - 1991.
CY  - Menlo Park, CA :
AU  - Rytuba, James J.
AU  - Cox, Dennis P.
VL  - 91-116
CN  - I 19.76:
PB  - U.S. Geological Survey,
PP  - Menlo Park, CA :
PY  - 1991.
N1  - Distributed to some depository libraries in microfiche.
ID  - 241496
KW  - Porphyry
TI  - Porphyry gold :a supplement to U.S. Geological Survey bulletin 1693 /
ER  -