TY  - RPRT
TI  - Nitrate in the Mississippi River and its tributaries, 1980 to 2008: Are we making progress?
AU  - Lori A. Sprague
AU  - Robert M. Hirsch
AU  - Brent T. Aulenbach
PY  - 2011
DO  - 10.1021/es201221s
UR  - https://pubs.usgs.gov/publication/70006337
ID  - 70006337
ER  -