Grey literature refers to research that is unpublished or has been published in non-commercial form. It is generally produced by industry or government bodies, private companies, charities, non-profit organisations, special interest groups, think tanks, professional associations, businesses, universities and more. Much grey literature is now freely available on many websites. However it is only selectively indexed in health databases.
Examples of grey literature are:
- conference papers/conference proceedings
- theses
- clinical trial registers
- guidelines
- newsletters
- pamphlets
- reports
- fact sheets, bulletins
- government documents
- surveys, interviews
- informal communication (e.g. blogs, podcasts, email)
In health sciences grey literature is vital for developing a more complete view of research on a particular topic or for producing systematic reviews.
