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Information Sources: Grey Literature

This guide will assist you in choosing the best sources for your information needs.

What is Grey Literature?

A scann of the cover of Soren Kierkegaard's university thesis, which is an example of gray literature."Grey Literature is any literature that has not been published through traditional means. It is often excluded from large databases and other mainstream sources. Leaving grey literature out of a systematic review excludes a major section of the available research. To avoid bias and to ensure that the review is as thorough as possible, always search grey literature" (University of Toronto, 2017, para. 1-2). It includes documents such as:

  • Unpublished conference papers
  • Unpublished theses and dissertations
  • Presentations
  • Working papers
  • Notes and logs kept by researchers
  • Academic courseware, professors' teaching notes, students' lecture notes
  • Company annual reports
  • Project and study reports
  • Institutional reports
  • Technical reports
  • Reports put out by government agencies
  • Data and statistics
  • Unpublished letters and manuscripts
  • Patents, technical standards
  • Newsletters, product catalogs, and certain other types of ephemera with a strong informational value
  • Preprints of articles
  • And much more!

Certain kinds of grey literature can be found in databases. Others are best found by searching the web. Sometimes it is difficult to ascertain the author or organization responsible for the information, which can make gray literature difficult to cite.(SUNY Empire State College, 2017)

Finding Grey Literature

Grey literature is not easy to find, which is why it's "grey"! Expect to have to do quite a bit of searching. That being said, with more and more information being published online, it's become a bit easier.

Government agencies, research institutes, organizations, companies or associations will often have a link to "research" or "publications" on their website.  If the body produces a large quantity of publications, then they might even have a "database" or "institutional repository" available for searching. 

It is helpful if you know which bodies publish in your area of research interest, but if you don't know where to look, you have a few options:

  1. Speak with your instructor. He/she might be able to point you to relevant resources
  2. Speak to a librarian. 
  3. Use Google or Google Scholar.  Because Google indexes a vast amount of the World Wide Web, you should be able to find a good amount of grey literature just through keyword searching, especially if you use the advanced search features which allow you to filter to specific website domains. (Royal Roads University, 2017)

Grey Literature

Western University. (2012, September 4). Grey literature tutorial [Video file]. Retrieved from