TY  - RPRT
TI  - Introduction to the U.S. Geological Survey National Water-Quality Assessment (NAWQA) of ground-water quality trends and comparison to other national programs
AU  - Michael R. Rosen
AU  - W.W. Lapham
PY  - 2008
DO  - 10.2134/jeq2008.0049
UR  - https://pubs.usgs.gov/publication/70009719
ID  - 70009719
ER  -