http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Nitrate in ground water and stream base flow in the lower Susquehanna River Basin, Pennsylvania and Maryland
National Water-Quality Assessment Program (U.S.)
x, 66 pages : illustrations (some color), color maps ; 28 cm.
"National Water-Quality Assessment Program."
"Lower Susquehanna River study unit"--Cover.
Includes bibliographical references (pages 64-66).
Water-resources investigations report ; 97-4146