Escherichia coli concentrations in recreational streams and backcountry drinking-water supplies in Shenandoah National Park, Virginia, 2005-2006 [electronic resource] / by Kenneth E. Hyer ; prepared in cooperation with the National Park Service.
Imprint
Reston, Va. : U.S. Dept. of the Interior, U.S. Geological Survey, 2007.
Mode of access: Internet at the USGS web site. Address as of 8/15/08: http://pubs.usgs.gov/sir/2007/5160/pdf/SIR2007-5160.pdf; current access is available via PURL.
Note
Title from PDF title screen (viewed on Jan. 14, 2008).