http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Distribution of selected nitrogen compounds in ground water and the unsaturated zone, Superior-Hardy Special Protection Area, Nuckolls County, Nebraska, 1991-93
v, 54 pages : illustrations, maps ; 28 cm.
Includes bibliographical references (pages 34-35).
Water-resources investigations report ; 96-4239