Where to Begin?
The resources on this page provide a general starting point to searching for grey literature.
Here you will find links to databases that specifically collect and index grey literature documents. The search engines found on this page have been designed to conduct broad searches across global databases, including the deep web. The preformulated search strategies have been designed to filter for specific types of grey literature such as non-governmental documents.
As the scope of grey literature is extremely broad, Sayre recommends considering the following questions in order to narrow down your search https://www.slideshare.net/fdsayre/introduction-to-grey-literature-for-health-sciences - slide 8:
- Who are your stakeholders?
- Government?
- Non-government?
- Academic?
- What kinds of literature are you interested in?
- Theses and dissertations?
- Conference proceedings?
- Reports?
- Statistics?
- What time period or geographic/geopolitical area is relevant to your search?
If you are conducting a systematic review, see Paynter's checklist of resources that covers three specific categories: regulatory information, trial registries, and abstracts & conferences.
Still have questions - contact a librarian for help starting your search of grey literature.
Lists of Databases
The resources below contain lists of the many databases that can be searched for grey literature.
- GreySourceProvides links to sources of grey literature categorized by subject.
- Canadian Agency for Drugs and Technologies in Health (CADTH)Link to database and resource "Finding the Evidence: Literature Searching Tools in Support of Systematic Reviews". Also includes links to additional information on searching grey literature.
- GreyNet International Directory of Organizations in Grey Literature This link opens in a new windowInternational Directory of Organizations in Grey Literature.
Databases
These resources broadly collect and index grey literature such as white papers, policy documents, summaries and more on global health topics. Resources are grouped geographically (American, European). Resources requiring USC login are listed last.
- US National Technical Information Service (NTIS)NTIS provides access to the results of both US and non-US government-sponsored research. Goes back to 1964.
- Eldis This link opens in a new windowOpen access database includes over 40,000 summaries and provides links to diverse full-text research and policy documents on development, policy, practice and research.
- ProQuest This link opens in a new windowDatabases of resources for arts, business, humanities, social sciences, science and newspaper resources.
PubMed Tools
PubMed databases, features, and preformulated search strategies.
Search Engines
The search engines below function similarly to Google, but contain features and filters useful for retrieving globally dispersed grey literature documents. These resources are organized first by broadest global perspective, and then by range of topic coverage from broadest to narrowest.
- World Wide Science - The Global Science Gateway This link opens in a new windowMutilateral partnership allows for search of national scientific databases in over 70 participating countries. Includes papers, multimedia, data, and public access content. Search available in Arabic, German, Spanish, French, Chinese, Korean, Portuguese, Russian, and Japanese.
- MedNar - Deep Web Search Engine This link opens in a new windowFree medically-focused deep web search engine that searches publically available authoritative medical and health resources that generally cannot be found through a typical Google search. Results include both black and grey literature.
- Science.gov This link opens in a new windowThis search engine provides access to free journal articles, peer-reviewed accepted manuscripts, and reports of research funded by federal science agencies. Topics include health and science, agriculture, environment, informatics, etc.
- MetaLib This link opens in a new windowSearches multiple U.S. federal government databases. Includes health, environment, agriculture, business, education, history, and more.
- AHRQ - Research Summaries, Reviews, and ReportsFind AHRQ research results: research reports, statistical briefs, horizon scans, EHC contracts and projects.
- BASE Search EngineBielefeld University Library's search engine for academic web resources. BASE searches over 6,000 sources, and about 60% of the indexed documents are available via Open Access.
- OpenMD.comOpenMD searches billions of documents from government agencies, global health organizations, medical journals, and reference sites.
- TRIP Database This link opens in a new windowThis clinical search engine allows users to quickly find high-quality research evidence to support practice or care. It also searches for images, videos, and patient education handouts.
Google Tools
Google databases and preformulated search engines.
- Google Scholar This link opens in a new windowFiltered Google Search finding scholarly journal articles, books, citations, and case law.
- Google custom search for Non-governmental OrganizationsSearch of Non-Governmental Organizations (NGOs) websites.
- Google custom search for Intergovernmental OrganizationsSearch for research on intergovernmental organization topics.
- Google Think Tank SearchThink Tank Search is a custom Google search of more than 600 think tank websites. For the purposes of this search, think tanks are defined as institutions affiliated with universities, governments, advocacy groups, foundations, non-governmental organizations, and businesses that generate public policy research, analysis, and activity.
Other
These resources can be used to get in contact with researchers or to search for unpublished study information.
- FigShare This link opens in a new windowData output repository. Includes datasets, posters, and presentations across arts and sciences.