TY  - RPRT
TI  - Monitoring cyclical changes in U.S. metals activity
AU  - Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey
PY  - 1998
DO  - 10.3133/fs07198
UR  - https://pubs.usgs.gov/publication/fs07198
ID  - fs07198
ER  -