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Grey Literature in the Health Sciences: About Grey Lit

Describes what grey literature is, why it is important to search it, how to focus your search, which resources are available to search, and how to evaluate grey literature. License: Creative Commons Attribution-NonCommercial Share Alike 4.0 International.

About Grey Literature

What is grey literature?

“…information produced on all levels of government, academia, business and industry in electronic and print formats not controlled by commercial publishing i.e. where publishing is not the primary activity of the producing body.”

Schöpfel, J. Towards a Prague definition of grey literature. Twelfth International Conference on Grey Literature: Transparency in Grey Literature. Grey Tech Approaches to High Tech Issues.Prague, 6-7 December 2010, Dec 2010, Czech Republic. pp.11-26. sic_00581570. Available from: 

Why is it important?

In the health sciences, grey literature is crucial in completing the picture of research on a particular topic. Grey literature can be an important source for:

  • recent results, data and statistics
  • reports are often more detailed in nature
  • publication lag (results may show up in conference proceedings months or years before they show up in peer reviewed journals)
  • positive result bias (study results with negative results are often published less in scholarly journals compared to those studies which showed a positive result)

How is it different from traditional published literature?

  • not widely disseminated
  • difficult to find
  • may contain more information as there aren't publication length stipulations 
  • can be produced and disseminated much faster than published literature
  • lower costs than traditional literature
  • may not go through as rigorous of a peer review process
  • often not archived

What types of sources can be grey literature?

  • policies or procedures
  • guidelines  
  • conference proceedings, papers or posters  
  • dissertations and theses
  • clinical trials  
  • leaflets and factsheets
  • and much more (list from

Source Guide:McMaster (see link and license below)

Grey Literature Tutorial (Western University) - A description about what grey literature is and how it can help you, the researcher.

Grey Literature is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International license.

View license information under YouTube video.

Archived (NOT CURRENT) Sources about Grey Literature

These were highly regarded sources about grey literature, but they are no longer updated and are not available as current web pages. These links are from the Web Archive (Wayback Machine).

Despite their lack of currency, they may be useful (at least in the short term) as background information. 

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We gratefully acknowledge that the content of this guide (including links, descriptions, and selected categories) is reused/remixed from the following guides and sources under a Creative Commons Attribution NonCommerical ShareAlike 4.0 International License.

Confirmation of the Creative Commons status of the entire USC guide was also sought and received in writing from the USC Guide Author Karin Saric on 11 July 2019. Reuse permission was granted provided attribution is given.

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