Google Scholar Link to Google Scholar Indexes the full text and metadata for scholarly literature, including NTL's digital repository ROSA P.
Science.gov Link to 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. Sources are from 13 federal agencies, including US DOT and NTL's digital repository ROSA P.
USA.gov Link to USA.gov Online guide to government information and services. Searches across all government websites.