TY  - RPRT
TI  - Ground-water levels in the United States, 1971-74, northwestern states
AU  - Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey
PY  - 1977
DO  - 10.3133/wsp2161
UR  - https://pubs.usgs.gov/publication/wsp2161
ID  - wsp2161
ER  -