Grey literature emerged as a field within library and information science several decades ago. It is concerned with the production, distribution, and access to documents of multiple types that are produced at all levels of government, business, academia, and other organizations. Whether in print or electronic format, grey literature is distinguished by being produced outside of and not controlled by commercial publishing entities.

Grey Literature Documents

Grey literature documents are often non-conventional and sometimes ephemeral publications. They may be available to the public, but frequently are only distributed privately within organizations or groups. Standards of quality, review and production vary. Systematic venues of distribution and collection may also be lacking.

Grey literature is particularly important as a means of distributing scientific, technical, public policy and practice information. Its relative importance varies with the research discipline or subject, and largely depends on the methodological approaches, and on the sources used. Some fields, such as medical and the life sciences, have a traditional preference for using peer-reviewed academic journals; but in aeronautics, agriculture, and the engineering sciences, grey literature predominates today.

Due to its very nature, librarians have had difficulty acquiring and making such material accessible to their patrons.  It generally lacks strict or meaningful bibliographic control, and basic information, such as authors, publication dates and publishing or corporate bodies, may not be easily identified or found.

While the difficulties and costs of finding and cataloguing grey literature mean that it is still not easy to find large collections, there are various databases and libraries that specifically target, collect, and make available print and digital grey literature. Much more detailed information can be found at: www.greylit.org and www.greynet.org .