International studies: Grey literature

​Grey literature is "Information produced on all levels of government, academics, business and industry in electronic and print formats not controlled by commercial publishing i.e. where publishing is not the primary activity of the producing body.

CGL Luxembourg definition, 1997-expanded in New York, 2004

Grey literature is published informally or non-commercially, or remains unpublished. It can appear in many forms, including government reports, statistics, patents, conference papers and even non-written resources such as posters and infographics.

Grey literature has not usually been peer reviewed, but may still be good, reliable information.  

It is produced from a variety of sources including industry, think tanks, and government departments, and is usually not indexed or organised which can make it difficult to locate.

Grey literature differs from "black literature" which is the familiar peer-reviewed publications found in commercial publishers' databases.

Grey literature could be used as a primary or secondary source. 

A short video explaining grey literature from Western Universities library

Grey literature is used in research because:

• It will often be more current than traditionally published sources, with a better coverage of emergent research areas. 
• A literature search that accesses only “black literature” will likely miss information vital to research.
• It can be a better source of information on policies and programs.
• Grey literature is often a good source of raw data and data sets to which you wouldn’t otherwise have access.

For a comprehensive listing of grey literature types view the greynet.org table.