Technical reports detail the process, progress or results of a project or investigation that are submitted to the sponsor of that project. They include in-depth experimental details, data and results. They are produced by both the government and non-government agencies. Technical reports are also known as working papers.
Australia.gov.au - Technical reports available on Australian Government websites
National Technical Reports Library (US) - NTRL is the preeminent resource for accessing the latest US government sponsored research, and worldwide scientific, technical, and engineering information.
IEEE Xplore - publications from the IEEE(Institute of Electrical and Electronics Engineers) and its publishing partners, including teh IET(Institute of Engineering and Technology)