"Grey Literature" consists of unpublished research (often of a scientific or technical nature) that is produced by government agencies, universities, corporations, research centers, associations and societies, and professional organizations. The typical bibliographic sources, such as library databases or indexes, rarely contain these types of documents.
Technical reports are a rich source of information produced by researchers and practitioners and describe the progress or results of scientific or technical research and development. They are often produced as part of sponsored research or as a response to a specific request or research need. A large subset of technical reports are the result of federally funded research often performed under contract to companies, universities and laboratories. Engineers especially depend heavily on technical reports.
Though they are not peer-reviewed, they are often the only source of some technical informationt that may not be available elsewhere. Due to their nature, they can often be produced rapidly so that the information can be shared with others working in the field.
Technical reports also have the function of "time-stamping" intellectual property on an innovation or development - important in the race to obtain patents.
Listed below are several major technical report databases mostly from US federal agencies. This is an evolving list.
If the report is not available for download, you can request via the ILLIAD Interlibrary Service.
Grey literature, due to its diverse origins and unpublished nature, can be difficult to find. Grey literature is often found by searching for the agency or institution most likely producing the literature. The search may require looking at a large number of sources. The Internet has made the dissemination of gray literature easier and advances will continue in the future.
Here are a few places to start looking for grey literature: