Grey literature is the "wealth of knowledge and information produced by organizations, governments and industry, covering a wide range of subject areas and professional fields, not controlled by commercial publishing." (Pisa Declaration 2014)
When conducting a systematic review it is important to include literature that has not formally been published in sources as it helps to prevent publication bias. Searching grey literature is supported/mandated by the Cochrane Collaboration, the Campbell Collaboration, JBI and the Institute of Medicine (U.S.).
Scope for key systematic reviews on your topic and explore what grey literature options are mentioned in Methods section.
Explore grey databases.
Consult trials registers to detect ongoing and unpublished studies.
Find publications on web sites of key organisations, professional associations, government departments/services and key authors.
Search Google Advanced/Google Scholar.
TIP! Conduct broad searches and document which resources you search.
These guides may help you decide which grey literature to search:
There are dissertations/theses specific databases such as ProQuest Dissertations & Theses.
Google Scholar includes dissertations/theses.
Google Scholar includes conference papers.
Relevant key organisations may hold conferences and make their proceedings available. Examples:
The Flinders University developed a useful tool for evaluating grey literature:
Alphabetical listing of clinical trials registers, York Health Economics Consortium
Examples of national and international trials registers, Cochrane Handbook, 4.3.3
Limit searches by site/domain or filetype, e.g.
Information on this page is mainly drawn from:
Tyndall, J 2016, Systematic review searching: Grey literature, Australian Evidence Based Practice Librarians’ Institute, Flinders University, Adelaide, 9 December 2016.