http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Maps of estimated nitrate and arsenic concentrations for basin-fill aquifers of the Southwestern United States
Observed and predicted nitrate concentrations in basin-fill aquifers of the Southwest Principal Aquifers study area
Observed and predicted arsenic concentrations in basin-fill aquifers of the Southwest Principal Aquifers study area
National Water-Quality Assessment Program (U.S.)
1 online resource (2 maps) : color + 1 pamphlet (iv, 8 pages).
by Kimberly R. Beisner [and six others].
Title from title screen (viewed on May 21, 2015).
"National Water-Quality Assessment Program."