NTIS - National Technical Information Service: Search
Freely accessible version of the searchable catalog of government research information products.
Public Technical Reports
A searchable database of unclassified documents in the Defense Technical Information Center's Technical Reports Collection, including the full-text of many documents.
OSTI.GOV is the primary search tool for DOE science, technology, and engineering research information with over 70 years of scientific and technical information from DOE and DOE predecessor agencies, and it employs an innovative semantic search tool enabling scientists, researchers, and the public to retrieve more relevant information. OSTI.GOV has about 3 million total records.
From the Environmental Protection Agency, the site provides a searchable, Agency-wide catalog of science activities such as research, technical assistance and assessments, along with peer-reviewed products.
A gateway to selected authoritative science web sites and databases of technical reports, journal articles, conference proceedings, and other published materials. The web pages and the databases can be searched individually or simultaneously from the search page. The site also includes an Image Search feature as one of its Special Collections.
"A global science gateway—accelerating scientific discovery and progress through a multilateral partnership to enable federated searching of national and international scientific databases and portals." From the U.S. Department of Energy and the WorldWide Science Alliance.