Planning your search

Since grey literature covers such a broad range of information sources, it's not feasible to search for all of the grey literature on a topic. The grey literature that will be most useful to you, will depend on your discipline and the topic/question you're researching. 

Before you can start finding grey literature, you need a good understanding of the information you're looking for. This will determine where and how you search for grey literature sources. 

Ask yourself: 

• What types of grey literature sources do you need to find? Think about which item types would be most relevant to your research. For example, in disciplines like education, social work, and development studies, government reports and white papers will be really useful, particularly if you're looking into policies and their impacts.
   
• Why are you looking for grey literature on this topic? What information/perspectives are you looking to find in these grey literature sources that differs from the content of academic journal articles and books? For example, are you looking for industry or public perspectives on your topic? Is the academic literature not particularly current so you need to search grey literature for the most up-to-date sources?
   
• When: Are you interested in sources from a specific time period? For example, are you only interested in more current grey literature or sources from a particular time/event (e.g. during the pandemic)?
   
• Where: Are you focusing on a particular country or region for your research? You may want to search local government or organisation websites from that area. If you're using a database or search tool to find grey literature, make sure it covers the area you're interested in.

Where to Search

Once you've identified what kind of grey literature you're looking for, you can determine where to search. There are specific discovery tools for certain types of grey literature. See our guides for a list of resources and databases for finding these sources:

• Official Publications (including government documents)
• Theses and Dissertations
• Statistics and Data 
• Newspapers

You can also use broad internet search engines to find grey literature, particularly web content and organisational reports. Search engines are also helpful for initial scoping searches, to check what grey literature content is available on a topic.

See the Google Advanced Search page for guidance on how to use these search engines effectively to find grey literature. 

Subject-specific grey literature sources

Some types of grey literature are specifically relevant for particular subjects. For example, business research draws on company and industry reports and business data. For engineering and informatics, patents and standards are very relevant. There are often search tools designed specifically for these subjects. 

Grey literature in academic databases

Certain types of academic grey literature are often included in research databases like Scopus, Web of Science, and other subject-specific search tools, usually in the form of scholarly research that has not yet been formally published. This includes: 

• Conference proceedings: A published collection of papers, presentations, and abstracts, shared during a conference. Conference documents can be published formally as journal articles, published separately, posted online on a conference website or made available via institutional repositories.
  
• Preprints: publicly shared, complete drafts of research papers that have not yet undergone formal peer review or been published in a scholarly journal, allowing for rapid dissemination and early feedback.
• Working Papers: research articles that are in the process of being submitted for publication in a journal, and have been shared online to present the research and gather feedback.

Many of these academic search tools will search for these grey literature sources automatically, along with published books and journal articles. To limit your results to just these grey literature sources, look for an 'item type' filter, and select the type of publication(s) you want to see e.g. 'conference proceedings'. 

These sources are useful for: 

• Providing information on new and emerging research.
• Specific subjects. For example, conference proceedings are a key source for disseminating research in engineering, and pre-prints are used commonly in the sciences, particularly physics. 

Keep in mind:

• Aside from conference papers that have been fully published as journal articles, these sources have not undergone peer-review.
• These sources present research that's still in progress, so the the content could change.
• Conference papers and proceedings offer brief summaries rather than presenting the research in full detail. 

Citation Searching

Citation searching is a valuable technique for finding grey literature, as it allows you to trace references to and from relevant documents. This approach helps uncover grey literature that may not appear in standard database searches.

Key Strategies:

• Backwards Citation Searching: Review the reference lists of journal articles, books, and other grey works related to your topic. These often cite other grey literature sources.
   
• Forward Citation Searching: Identify works that have cited a key document you already have. This can reveal more recent grey literature sources building upon earlier work. Tools like Google Scholar, Scopus, and Web of Science are especially useful for forward citation tracking.

Several tools facilitate effective citation searching for grey literature:

Citation searching is a powerful technique for uncovering grey literature that may not appear through standard search methods. Using tools like Google Scholar you can discover a range of grey literature sources by starting from a report or primary research article in a journal.

Keeping a record

Because grey literature is not formally published, it's not fixed. The information could be changed or the source could be removed completely so it's important to keep a record of any grey literature sources you find. 

Make a note of the date you accessed the source and the URL. You'll need this when referencing the source later. Keep in mind links for grey literature, unless found in an institutional repository, may not be maintained, so you should also save a copy of the source.

Using a reference management tool like Zotero can help you keep track of grey literature. See our Zotero Guide for guidance.

Next Section: Using Google's Advanced Search

Google Advanced Search provides powerful tools to refine your search and uncover grey literature that may not appear in standard search results. The next section will introduce techniques for using Google Advanced Search effectively to locate high-quality grey literature.