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Physician Assistant (PA) Program

Grey Literature Defined

This guide contains links to databases, search engines, and websites relevant to some of the more commonly searched types of grey/gray literature in the health sciences: policy positions, reports, briefings, evaluations of programs, white papers, clinical trials, regulatory information for drugs and medical devices, grants, theses & dissertations, conferences, documents from professional organizations, and statistics.   Click here for a comprehensive list of grey literature document types.

Grey/Gray Literature deals with the production, distribution, and access to multiple document types produced on all levels of government, academics, business, and organization in electronic and print formats, not controlled by commercial publishing.  GreyNet International

It is benefical to search the grey literature when creating comprehensive health care documents such as guidelines, systematic reviews, and meta-analyses, as the information contained in such documents can provide a broader perspective which is useful in reducing bias.  

Since much of grey literature is unpublished or published through non-commerical avenues it can be difficult to find.  For detailed guidance on how to search the grey literature, please see the guides listed in the box to the right.   

Resources listed in this guide are freely available, unless otherwise noted.

Types of Grey Literature

This diagram provides a visual representation of the various sources and types of grey literature commonly searched when conducting a systematic review:

Image obtained from: Rose Relevo Slide Presentation from the AHRQ 2011 Annual Conference 9/20/11