Quality of nutrient data from streams and ground water sampled during water years 1992-2001 [electronic resource] / by David K. Mueller and Cindy J. Titus.
Imprint
Reston, Va. : U.S. Dept. of the Interior, U.S. Geological Survey, 2005.
Mode of access: Internet at the USGS web site. Address as of 9/2/08: http://pubs.usgs.gov/sir/2005/5106/pdf/sir2005-5106.pdf ; current access is available via PURL.