United States National Technical Information Service. text Oakridge, Tenn National Technical Information Service U.S. Geological Survey Dept. of Energy, Office of Scientific and Technical Information [2003]- monographic Title from title screen (viewed Dec. 16,2003) Science C 51.22:2003019573 C 51.22:2003019573 http://purl.access.gpo.gov/GPO/LPS41277 http://purl.access.gpo.gov/GPO/LPS41277 20160527183619.0 299497