Works created by the United States federal government are public domain. This does not apply to works by other government entities, grant recipients, or contractors.
Catalog of U.S. Government Publications
records and direct links to historical and current publications
MetaLib
searches multiple U.S. Federal Government databases for links to reports and other materials
Science.gov
U.S. government science information, research, and development results from federal databases and websites
National Technical Reports Library (Public NTRL)
index to National Technical Information Service (NTIS) publications 1990-present
CDC Stacks
digital archive of scientific research and literature produced by the Centers for Disease Control and Prevention
Defense Technical Information Center (DTIC)
top resource for Department of Defense (DoD) information and related government-funded research
National Criminal Justice Reference Service (NCJRS)
summaries of criminal justice resources in the NCJRS Library
National Service Center for Environmental Publications
search, view, download, and purchase Environmental Protection Agency (EPA) publications
National Library of Energy
project descriptions and results from the U.S. Dept. of Energy's Office of Scientific and Technical Information (OSTI)
USGS Publications Warehouse
U.S. Geological Survey (USGS) publications including maps from 1880-present
Scientific & Technical Information (STI) Program
NASA and NACA reports, conference papers, articles, images, and videos
TRID
records from the Transportation Research Information Services and International Transport Research Documentation databases