Finding grey literature

Finding grey literature

Grey literature is information like theses, reports, conference proceedings, clinical trials, policy documents or guidelines. This can be produced by a wide variety of sources such as national or local government, charities, or academics. It can be hard to find as it can "fall through the cracks" and not be indexed in the main databases and sources. This page outlines the main sources in health, but you should always consult the handbooks for the type of review you are conducting.

Clinical trials
  • The National Institute for Health Research covers Research carried out in England and has a searchable archive which covers UK wide older research.
  • produced by the US National Library of Health. This indexes trials in the US and worldwide.
  • CenterWatch as a searchable database of listings of worldwide industry and government-sponsored clinical trials. Sponsors use this service to inform patients and their caregivers about ongoing clinical trial opportunities, which volunteers can then review and inquire about participating in.
  • Current Controlled Trials allows users to search, register and share information about randomised controlled trials. Access to all the information on this site is free.
  • Trials is an open access, peer-reviewed, online journal from BioMed Central that covers the performance and findings of randomized controlled trials.
Search engines

You can find a lot of useful information on the internet, but it can be hard to search and to judge the quality of what you find. Some search engines have an advanced search feature which helps filter out some of your search results. There are also more focused search engines such as Google Scholar, which search academic publications.

Here are some general tips to help you:
  • use the advanced search option
  • don’t use truncation
  • AND is the default which means that the words you type must all be mentioned, link synonyms using OR
  • specify the domains gov, ac or org
  • limits:
    • exact phrase (don’t use truncation)
    • with at least one of the words
    • in the title of the article
  • DART-Europe - browse and search open access theses.
  • EThOS - British Library site with free searching of UK PhD theses. Some full text items available. Register or login to order an electronic version of a thesis. Use the advanced search to combine search terms with ‘And’, ‘Or’ or ‘And NOT’. Searches on Thesis Title, Abstract, LCSH (Library of Congress Subject Headings) and Subject Keyword are some of the options available.
  • ProQuest Dissertations and Theses, part of ProQuest Central. Provides summary information only.
  • Networked Digital Library of Theses and Dissertations.

This page was produced in collaboration with Dr Helen Marlborough of Glasgow University Library.