http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Water-quality assessment of the Potomac River Basin
analysis of available pesticide data, 1972-90
Water quality assessment of the Potomac River Basin
National Water-Quality Assessment Program (U.S.)
"Prepared as part of the National Water-Quality Assessment (NAWQA) Program."
Includes bibliographical references (pages 75-77).
Water-resources investigations report ; 97-4051