TY  - RPRT
TI  - Metallogenetic eras and periodicity in earth history
AU  - A.P. Pierce
AU  - Ralph Smyser Cannon
PY  - 1969
DO  - 10.3133/ofr69204
UR  - https://pubs.usgs.gov/publication/ofr69204
ID  - ofr69204
ER  -