TY  - RPRT
TI  - Detecting changes in the spatial distribution of nitrate contamination in ground water
AU  - Z.-J. Liu
AU  - G.R. Hallberg
AU  - D.L. Zimmerman
AU  - R.D. Libra
PY  - 1997
UR  - https://pubs.usgs.gov/publication/70019208
ID  - 70019208
ER  -