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Public Health: Grey Literature

What is Grey Literature?

Grey literature is information produced outside of commercial publishing and distribution, including:

  • Government information (international/ federal/state/local) 
  • Conference/symposium proceedings and abstracts
  • Informal communications and translations
  • Newsletters and annual reports
  • Patent applications
  • Registered clinical trials
  • Drug information
  • Research reports (completed and uncompleted)
  • Technical reports and whitepapers
  • Theses and Dissertations
  • Blogs, Listserv archives, tweets
  • Podcasts and videos
  • Images, maps, and spatial data
  • Websites, repositories, digital libraries

Grey (or gray) literature can be more current than traditional sources, but since it does not go through the peer-review process the quality may be variable and all sources must be critically evaluated. Researching grey sources can help identify a gap in the literature, and may offer a fuller picture and/or balance possible biases in commercial publications.

General Resources

AHRQ Report: Finding Grey Literature 

Grey Literature Publishers List

Medline Plus Organization Directory: search individual organizations of interest for reports, conference proceedings, newsletters, guidelines, etc

NIH Health Services Research Projects in Progress

WHO: World Health Organization: reports and guidelines on public and global health topics

Search Strategies

Tricks for finding unpublished material in Google and Google Scholar

  • Use quotes around a phrase to force specific word order.
  • Use quotes around a word to turn off synonyms, plurals, and spell-checking.
  • Specify domains such as .org, .ca, or .gov.
  • Search within a website or domain by adding site: in front of it.
  • Specify file types .pdf, .ppt, .doc.
  • Search social media: @twitter, #hashtags.
  • Check variant spellings to find Canadian, British, and American English.

Note: advanced search techniques such as truncation, boolean operators, and nesting terms do NOT work in ordinary Google searching. Use Advanced Search to access more options.

Custom Searches

NGO Search: non-governmental organizations

IGO Search: international government organizations

DataCite: locate datasets, program files, images, and other research material