Searching for grey literature
Grey literature is usually not as well indexed as traditional research. Developing a search for grey literature shares some similarities with traditional database searching, such as the use of keywords and search operators. However, tools such as search engines often have limited search functionality and may require simpler search queries with an increased emphasis on using filters/ limiters or on screening results for relevance.
Where to search for grey literature
Key sources for grey literature vary depending on the type, and include specialised databases, repositories and search engines. Artificial intelligence (AI) search engines are increasingly valuable in identifying grey literature.
Traditional search engines
Search engines crawl the web, index websites, rank them, and display results matching user queries. Algorithms consider prior search activity, so results may vary for different users. While searches aren't replicable, reporting the search can aid transparency. In general, keep searches simple.
- Google
Useful for finding publicly available information, e.g. government information, policy documents, or environmental data. However, your search history in Google can influence the search results you recieve.
- DuckDuckGo
Useful for finding publicly available information. DuckDuckGo doesn't track users, so your search results are not influenced by previous searches.
Tips for using a Search engine
- Use keywords: Include relevant grey literature terms like "policy," "report," "white paper," or "thesis" along with main concept keywords from the research question. Search engines often automate searches for alternative terms and endings, avoiding the need for synonyms or truncation.
- Develop concise searches: Many search engines have search character or word limits.
- Use search engine syntax: Make use of search engine operators to tailor the search, including exact phrasing and site limiters. Google and DuckDuckGo use similar operators.
- For further information on Google search engine operators check out Google search operators and Advanced search operators for Google. For further information on DuckDuckGo search engine operators check out DuckDuckGo search operators and Ultimate Guide to DuckDuckGo.
- For further information on Google search engine operators check out Google search operators and Advanced search operators for Google. For further information on DuckDuckGo search engine operators check out DuckDuckGo search operators and Ultimate Guide to DuckDuckGo.
- Use limit functions: Limit search results to organisation type or geographic area using URL domain limits (for example, include site:.edu.au in the search to limit results to websites from Australian educational institutions). Explore country domain limits
AI search engines
Semantic search tools are designed as conversational search tools. They work best with natural language questions instead of keyword-based searches. It’s important to note that searches with these tools are not replicable and may not be suitable for systematic reviews. They are also subject to bias and all output should be critically evaluated
- Perplexity.ai
An AI search engine that searches the web and provides a concise summary of findings along with sources to explore.
- Felo.ai
Similar to Perplexity this AI search engine crawls the web and provides a summary of findings along with sources to explore.
- Semantic Scholar
This AI search engine primarily seeks to find information from academic sources, but also includes preprint articles.
Specialist databases and repositories
The focus of specialist databases and repositories are often maintained by government, academic or not-for-profit organisations. They often provide help or instructional material on their search functions. In general, keep searches simple with a few key search terms and simple search operators.
- Australian Government Publications Portal
Find Annual Reports, Corporate Plans and Portfolio Budget Statements from Commonwealth government bodies.
- Australian National Data Commons
Contains reusable research datasets that are considered to be important to the Australian research community.
- Dimensions
A comprehensive database that capture research outputs includes working papers, policy documents and clinical trials. Register free account provides users with limited access.
- GreyNet
Provides comprehensive information and resources on grey literature.
- OpenDOAR
An authoritative directory of 2,000 academic open access repositories with freely available academic research information.
- Overton
A searchable index of policy documents, guidelines, think tank publications and working papers.
- Policy Commons
A collection of objective, fact-based research from the world's policy experts, think tanks, IGOs and NGOs. Includes Australian content from national and state governments.
- Trove
Discovery platform focused on Australia, Australians, and items found in Australian Libraries. It includes material held in Australian university, library, museum and gallery collections.
Further details on specialised search sources for different types of grey literature can be found in other sections of this guide.
Grey literature that is no longer accessible
Where grey literature material has been retired, removed or is otherwise no longer accessible, you can conduct a search using the Internet Archive Wayback Machine for previous versions of websites.
Caution
The Wayback Machine is unavailable on Deakin computers but is accessible via personal devices.