The NASA Science & Technical Information [STI] Repository (also known as the NTRS) provides access to NASA metadata records, full-text online documents, images, and videos.
Science.gov searches over 60 databases and over 2,200 scientific websites to provide users with access to more than 200 million pages of authoritative federal science information including research and development results.
From the US Department of Commerce, NTRL was created by the National Technical Information Service as a means of dissemination federally scientific, technical, engineering, and business information.