Grey (or gray) literature is a term for literature not published in traditional research publication venues like scholarly journals. It includes theses, whitepapers, reports, policy documents, and government data.
Because this information is often self-published by an organization, it is typically not peer-reviewed. However, grey literature serves a really important function because:
"Reports" are a catch-all category of publication that presents information in a very concise manner, usually written at a basic reading level to appeal to many audiences at once, often used to educate non-experts in academia, corporate industry, government, or non-profit realms about a topic
Whitepapers are a very formal category of publication, similar to a report, but with an ultimate purpose of articulating an organization's opinion or position on an issue
A category of publication more defined by who has written it (students in pursuit of a degree) than its structure or purpose. Theses and Dissertations usually communicate original research, though they can be primary or secondary research, and functionally, they may identify gaps in available evidence, summarize some evidence, or even articulate an opinion or position.
Sets of data typically compiled by the US government, which are available for the public to download and use
With the exception of theses, grey literature is not held in academic databases. Instead, you can:
Similar to using Boolean commands, "power" searching gives you the ability to be very specific when you search google.
specify that search results contain certain filetypes, search for synonyms of your search terms, or only come from websites with certain kinds of urls, like .edu or .gov
site:gov (children AND "traumatic brain injury")
In the above example, results will all be government resources or websites
"clinical trials" inurl:braininjury
In the above example, "braininjury" must occur in the url of the search results
"traumatic brain injury" filetype:pdf
The search in the above example retrieves only items of the specified filetype
~guidlines "traumatic brain injury"
The above exampleretrieves results with synonyms to "guidlines"
children ~guidlines inurl:"traumatic brain injury"
The above example retrieves results which contain words that are synonyms to "guidelines", and have the words "traumatic brain injury" in the ur
Portions of the information on power searching are based on information taken from University of Michigan Library’s Libguide Dentistry: Power Searching
NGO Search is a Google Custom Search that searches across hundreds non-governmental organization (NGO) websites. NGO Search is a project of the International Documents Taskforce (IDTF) and the Government Documents Roundtable (GODORT) of the American Library Association (ALA).
International governmental organizations (IGOs) are organizations made up of more than one national government—examples include NATO (North Atlantic Treaty Organization) and the WHO (World Heath Organization). The governments are the members. IGO Search is a Google Custom Search that searches across IGO websites. It is a project of the International Documents Taskforce (IDTF) and the Government Documents Roundtable (GODORT) of the American Library Association (ALA).