TY  - RPRT
TI  - CHANGES IN GRADE, VOLUME AND CONTAINED GOLD DURING THE MINING LIFE-CYCLE OF GOLD PLACER DEPOSITS.
AU  - J. D. Bliss
AU  - G. J. Orris
AU  - W. D. Menzie
PY  - 1987
UR  - https://pubs.usgs.gov/publication/70015206
ID  - 70015206
ER  -