"Rising Smoke Column with Turbulence" by vladdythephotogeek is licensed under CC BY-NC-ND 2.0
"Royal Navy Submarine HMS Astute" by Defence Images is licensed under CC BY-NC-ND 2.0
+ Defense Technical Information Center (DTIC)
Search the DTIC database for technical reports funded by the Department of Defense (DoD S&T Reports); journal articles, conference papers, and related material that are the result of government-funded research (PubDefense); and technical data and analysis resources for identification and utilization of existing S&T information (DoD Information Analysis Centers).
+ NASA Technical Reports Server
Search the NASA Technical Reports Server for aerospace-related citations, full-text online documents, images and videos. Included on this site are conference papers, journal articles, meeting papers, patents, research reports, images, movies, and technical videos--scientific and technical information (STI) created or funded by NASA.
+ Office of Scientific and Technical Information
Search the U.S. Department of Energy’s Office of Scientific and Technical Information (OSTI) site for over 70 years of research results including journal articles/accepted manuscripts and related metadata; technical reports; scientific research datasets and collections; scientific software; patents; conference and workshop papers; books and theses; and multimedia.
Search Science.gov for results from over 60 databases and over 2,200 scientific websites that provide users with access to more than 200 million pages of authoritative federal science information including research and development results.
+ TRAIL-Technical Report Archive & Image Library
Search TRAIL for unrestricted access to U.S. government agency technical reports; millions of pages of elusive technical reports are discoverable through this library.
"Flying in formation" by Mustang Joe is marked with CC0 1.0
"Honey" by mynameisharsha is licensed under CC BY-SA 2.0