Western Libraries

Knowledge Synthesis: Systematic & Scoping Reviews

Grey Literature

What is Grey literature:

  • is not easy to find
  • can be produced and disseminated much faster than published literature
  • is less expensive to access than traditional closed-access literature
  • may not go through a peer review process
  • is information produced outside of traditional publishing and distribution channels, and can include reports, policy literature, working papers, newsletters, government documents, speeches, white papers, etc...
  • is not widely disseminated
  •  is often produced by organizations to store information and report on activities, either for their own use or wider sharing and distribution


“…unpublished research may be considered “grey literature.”… Grey literature is produced at all levels of government, academia, business, and industry in print and electronic formats not controlled by commercial publishers. Grey literature can include government reports, committee reports, academic papers, theses, bibliographies, conference papers and abstracts, discussion papers, newsletters, PowerPoint presentations, conference proceedings, program evaluation reports, standards/best practice documents, technical specifications and standards, and working papers(Alberaniet al. 1990). Because of the nature of grey literature, it is often difficult to access through mainstream databases, such as MEDLINE and CINAHL. The majority of grey literature is not peer-reviewed and has limited referencing of information.”
Benzies, K.M. (2006). State-of-the-evidence-reviews: Advantages and challenges of including grey literature. Worldviews of Evidence Based Nursing, 3(2), 55-61. Retrieved from http://www.nursingsociety.org/Publications/Journals/Pages/worldviews.aspx


For information on Grey Literature:

SuReInfo Grey Literature Chapter

Provides definitions, explanations, and instructions related to searching in grey literature sources. Last updated 15 March, 2023.


Different Types and Sources of Grey Literature

  • Canadian Health Research Collection
  • Dissertations and Theses Database - ProQuest
  • Conference proceedings
  • Newsletters
  • Reports
  • Government documents (including NGO's & IGO's)
  • Informal communication (meetings, telephone calls)
  • Videos
  • Technical reports
  • Census, economic & other data
  • Association, Organizations - Canadian Medical Association, Health Canada, World Health Organization, etc.
  • Web Search Engines - Google scholar

New Sources of Grey Literature & Data

  • e-prints, preprints, post-prints
  • emails, blogposts, even tweets
  • Web 2.0 communication channels
  • wiki articles & virtual worlds like Second Life
  • listserv archives 
  • digital libraries (i.e. Institutional Repositories)
  • grey (gray) data; spatial data (ie. Google Earth)
  • meta-searching, federated searching, portals
  • electronic & social networks
  • images, maps

Dean Giustini, UBC Biomedical Branch Librarian - March 2010.  ’Finding the hard to finds: Searching for the grey literature’

Grey Literature Checklists



Grey Literature Challenges
  • Grey literature can be regarded as less prestigious and less organized than published literature as is not always peer reviewed or fully edited.
  • It may include raw data and findings that are incomplete. 
  • Grey literature can be produced in various formats and be written in lots of different styles, therefore care must be taken when extracting complex data and information.
  • Papers, briefing documents and fact sheets, etc. from organizations might not always be unbiased.