The NASA Astrophysics Data System
http://adswww.harvard.edu/ popularThe Astrophysics Data System (ADS) is a NASA-funded project which maintains four bibliographic databases containing more than 4.0 million records: Astronomy and Astrophysics, Instrumentation, Physics and Geophysics, and preprints in Astronomy.
Submitted in section: Astrophysics: The NASA Astrophysics Data System