TY  - RPRT
TI  - A scientifically based nationwide assessment of groundwater quality in the United States
AU  - W.M. Alley
AU  - P. Cohen
PY  - 1991
DO  - 10.1007/bf01716071
UR  - https://pubs.usgs.gov/publication/70016795
ID  - 70016795
ER  -