http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
U.S. Geological Survey 21st-Century science strategy 2020-2030
United States Geological Survey 21st-Century science strategy 2020-2030
1 online resource (iii, 20 pages) : color illustrations, color maps.
Includes bibliographical references (pages 19-20).