DTIC Multisearch - Federated search from the Defense Technical Information Center
NASA Technical Reports Server - NTRS provides access to approximately 500K aerospace related citations, 90K full-text online documents, and 111K images and videos. NTRS numbers continues to grow over time as new scientific and technical information (STI) is created or funded by NASA. The type of information found in NTRS include: conference papers, images, journal articles, photos, meeting papers, movies, patents, research reports, and technical videos.
Worldcat - Worldwide catalog of libraries' holdings
ARIBIB - The ARIBIB is an on-line database for astronomical bibliography. Can be searched by an author index or a search form with various options. It does not contain abstracts.
Science.gov - Science.gov searches over 40 databases and 1,950 selected websites, offering 200 million pages of authoritative U.S. government science information, including research and development results. Includes Astronomy and Space, as well as Earth and Ocean Sciences subject categories.
Union List of Astronomy Serials (ULAS) - Bibliographic information for (primarily) non-commercial publications of observatories and institutions concerned with research in astronomy. To each of the approximately 2300 titles included are appended the holding records of 42 contributing libraries, representing the most comprehensive astronomical collections in North America, with selected holdings from China, Europe, India, and South America as well.
Annual Reports of Observatories - Searchable listing of those observatories that have annual reports and where to find them.
Library of Congress Astronomy/Astrophysics Tracer Bullet - LC Subject Headings, Bibliographies, and other resources on astronomy.