Grey literature is "Information produced on all levels of government, academics, business and industry in electronic and print formats not controlled by commercial publishing, primarily where publishing is not the primary activity of the producing body"(CGL Luxembourg definition, 2004)
Grey literature is literature that is not formally published in books or journals. It is produced from a variety of sources, and is usually not indexed or organised. By its very nature, grey literature can be difficult to locate.
It can take many forms:
| Conference proceedings | Government reports | PhD theses and dissertations | Information from key websites |
| Clinical trial summaries | Practice guidelines | Patents | Reports from relevant associations/public bodies |
| Maps | Census data | Working papers | Pre and post print articles |
| Technical reports | Blogs | White papers | Non-written resources and informal communications such as posters and infographics |
See more grey literature types: greynet.org table
Adams, J., Hillier-Brown, F.C., Moore, H.J., Lake, A. A., Araujo-Soares, V., White, M., & Summerbell, C. (2016). Searching and synthesising ‘grey literature’ and ‘grey information’ in public health: critical reflections on three case studies. Syst Rev, 5(164). doi:10.1186/s13643-016-0337-y
Adams, R. J., Smart, P., & Huff, A. S. (2017). Shades of Grey: Guidelines for Working with the Grey Literature in Systematic Reviews for Management and Organizational Studies. International Journal of Management Reviews, 19(4), 432–454. https://doi.org/10.1111/ijmr.12102
Bat, M., & Shore, S. (2012). Listening differently: an exploration of grey literature about Aboriginal teacher education in the Top End of the Northern Territory. MATSITI, Charles Darwin University, http://matsiti.edu.au/wp-content/uploads/2012/07/MATSITI-CDU-grey-literature.pdf.
Mahood, Q., Van Eerd, D., & Irvin, E. (2013). Searching for grey literature for systematic reviews: challenges and benefits. Research Synthesis Methods, 5(3), 221-234. doi:10.1002/jrsm.1106
Paez, A. (2017). Gray literature: An important resource in systematic reviews. Journal of Evidence-Based Medicine, 10(3), 233-240. doi:10.1111/jebm.12266
Including grey literature in your search strategy will help you discover
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