
1. Systematic reviewing: 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. A wider range of general resources is listed on our research support page.
Clinical trials
- The National Institute for Health Research (formerly the National Research Register) covers Research carried out in England and has a searchable archive which covers UK wide older research
- ClinicalTrials.gov 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.
- For a wide general search use Google advanced search
- For a search of academic level material use Google scholar advanced search
- Exalead
- Mednar - a free specialist medical search engine. Take a guided tour.
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
Theses
- DART-Europe - browse and search open-access research theses.
- EthOS - British Library beta site with free searching of more than 250,000 UK PhD theses. Some full text items available, but can be slow to download. 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.
- Index to theses – theses accepted for higher degrees in Great Britain and Ireland. The standard search allows you to combine search terms with ‘And’ or ‘Or’. For example search for ‘Ischaemic’ AND ‘Stroke’ in the Title field. For example search for ‘Health Promotion’ OR ‘Health Education’ in the Title field. Searches on the Abstract are not available in the Index to Theses.
- Networked Digital Library of Theses and Dissertations.
This page was produced in collaboration with Dr Helen Marlborough of Glasgow University Library.