Grey Literature

Grey literature refers to a wide range of publications that are not books or journal articles

Grey literature should be included in a thorough or systematic review of the literature as it can:

  • Reduce positive publication bias
  • Provide a wider range of information, especially from those who do not publish in academic journals (Practitioners, industrialists, victims, patients)
  • Have a strong local or regional flavour
  • Present government or other official policies
  • May be more detailed than conventional books or articles

Grey literature includes:

Social media such as Twitter or Facebook might also be classed as a form of grey literature.

Finding reports, discussion papers and working papers

General sources of grey literature include:

  • OpenGrey - a multidisciplinary European database for "grey literature"
  • BASE - the Bielefeld Academic Search Engine
  • Union catalogues such as Library Hub Discover or WorldCat include reports and theses

Many specialist databases and search engines (such as NHS Evidence) will help you find report and other grey literature on a particular subject. Many of them are listed in your subject guide.

You can search institutional repositories through services such as OpenDOAR

Another technique for finding reports is citation pearl searching – search Google Scholar for a key paper in your area and see the publications which have cited it – there may well be reports as well as journal articles.

Investigate people’s websites

People who are working in your field are a good source of grey literature. Start from their institutional webpages and check out their publication lists, where you may find reports alongside articles and books. Current activities/projects pages may also include grey literature. You may also be able to follow them on Twitter, Facebook, LinkedIn and other social media sites.

Searching organisations

As your work progresses, you’ll become aware of the main organisations active in your field – charities, pressure groups, learned societies, government bodies, research institutes. Do a thorough search of their webpages.

Evaluating grey literature

Grey literature has not been through any sort of peer review process. Therefore it is particularly important that you evaluate material very carefully to decide whether to use it.

The AACODS checklist is designed to enable evaluation and critical appraisal of grey literature:

  • A Authority
  • A Accuracy
  • C Coverage
  • O Objectivity
  • D Date
  • S Significance

It was prepared at Flinders University and there is a very helpful annotated checklist.