New and improved ADS. This version has more features than "Classic" ADS (see below), including smarter searching, better handling of references, ability to view author, object and paper "networks", etc. Note: To use this tool most effectively, you should consider creating an account.
A thematic, community-wide repository – curated by astronomy librarians and indexed monthly by the NASA ADS – collects theses and dissertations on astronomy and astrophysics. Share the full-text of your cumulative, graduate or PhD level, research with the world by uploading it as open-access to this subject based community.
The SIMBAD astronomical database provides basic data, cross-identifications and bibliography for astronomical objects outside the solar system. SIMBAD can be queried by object name, coordinates, other criteria (filters), and lists of objects.