The SPIE Digital Library is a comprehensive, online tool for locating papers on optics, photonics, optoelectronics, and imaging. Subject coverage is broad across optical technology, including astronomy, aerospace, remote sensing, biomedical optics, communications & fiber optics, electronic & medical imaging, lasers, microelectronics & micromachining, nanotechnology, optical physics, chemistry & biology, and signal & image processing. About 15,000 papers are added annually. The SPIE Digital library provides access to the papers published in: Proceedings of SPIE, Optical Engineering, Journal of Electronic Imaging, Journal of Biomedical Optics, Journal of Microlithography, Microfabrication, and Microsystems, Journal of Applied Remote Sensing, and Journal of Nanophotonics.

Search NASA reports, NACA documents and selected non-NASA archives in the fields of aeronautics, space science, chemistry and materials, engineering, geosciences, life sciences, mathematics and computer sciences, and physics.

Coverage: 1917-present
Tags: Aerospace, Aviation, Science, Space

NED is a database of approximately 750,000 extragalactic objects with bibliographic references and basic data.

Compendex is the most comprehensive bibliographic database of engineering research literature, containing references to over 5000 engineering journals and conferences. About half the citations (from 2600 journals and conferences) include abstracts and indexing in the records.