BASE is one of the world's most voluminous search engines especially for academic web resources. BASE provides more than 240 million documents from more than 8,000 content providers. You can access the full texts of about 60% of the indexed documents for free (Open Access). BASE is operated by Bielefeld University Library.
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.
Explore science from over 230 full-text eBooks! This collection of reference titles covers a wide variety of topics such as animals, biology, climate change, computing, engineering, experiments, life science, nature, oceans, physical science, and weather.