Grey literature

You may need to take a different approach to finding grey literature than when you search journal databases or are looking for books. Here are a few things to consider to improve your chances of finding relevant material.

Search interfaces used to find grey literature can be very basic. You might have to use fewer or broader search terms, or make several searches of the same resource using different combinations of search terms.

Develop a grey literature search plan before you start, and adapt it and keep track of what and how you have searched. See our literature searching advice for ways to do this.

Use a range of strategies to find what you need. Some suggestions include:

• use different search engines rather than relying on Google, for example, Google Scholar, Dogpile or DuckDuckGo
• target relevant organisations, for example, think tanks, organisations, agencies, regulatory or professional bodies, and search their websites or databases individually, rather than relying on a search engine alone
• search databases and library catalogues containing grey literature – results from these sources often don’t appear in a general web search
• consult with other researchers and experts who are working in the area of your research topic via email, social media platforms or academic mailing lists.

A lot of grey literature is hosted on websites and the content can be deleted or edited by the website owner at any time, so you should make a permanent record of any relevant material you find. Software such as Evernote or OneNote can help you store and organise this content.

Many web resources don’t provide a way for you to export results to reference management software such as EndNote. If you usually save a lot of search results at once and then review them to pick out the most relevant ones, you might have to change this to sift through results on screen. You could make a note of the relevant results or manually add them to your EndNote library as you search. Or you could take screenshots, or use web scraping tools such as Klipper or WebScraper to extract links from webpages and save them in .cvs file format, which can be imported into an Excel spreadsheet to work through later.