Grey literature refers to any information source that is not commercially published. As these sources are dispersed and not collected by centralised publishing platforms, they are sometimes difficult to find and can be tiresome to search.
What counts as grey literature?
Internal reports, such as government white papers
Meeting minutes and notes
Conference abstracts, papers
Theses and dissertations
Pre-print or unpublished research
Clinical trial data
Patents and technical standards information, such as British Standards (BSO) or International Standards (ISO)
Why use grey literature?
Often good quality information produced by experts in their field, e.g. white papers are commissioned by the government from a body of subject specialists
Providing important insights into the 'reality' of research, e.g. clinical trial data that is not published because the study was not successful and therefore not commercially beneficial
Reflects the expertise of individuals not associated with academia e.g. independent think tanks; charities representing oppressed groups or individuals; other industry experts (for example, in business or technology).
Conference proceedings are records of research which has just been presented at conferences before journal articles are written and so are good for finding very recent information.
What are theses and dissertations?
A thesis or dissertation is a long piece of assessed academic work usually submitted for an academic degree. A thesis is usually kept in the library of the university from which the author received his degree. (More information on Theses at UCL).