Doing a systematic review

Your search needs to be as exhaustive as possible, and include published and unpublished sources.

• Use more than one source.
• Don't rely on Google or Google Scholar.
• Use professional databases on which you can construct much more structured searches and comprehensive searches. 
• Try out potential databases and get to know them. Some databases use a controlled vocabulary (subject headings) which can help ensure you capture all the relevant studies, for example, PubMed/Medline uses MeSH (Medical Subject Headings).

Your Academic Liaison Librarian will be happy to help you identify possible places to search.

A scoping search is a quick search with basic keywords. Use it to:

• evaluate the amount of literature on a topic - will there be too much, too little or just the right amount?
• check if a database covers your topic
• help you discover and refine your search words
• key papers you identify by scoping searches can also be used to test your final search strategy - make sure they are coming up in your results

Summon as a starting point

You could start with the Library's discovery service Summon. This searches across all our subscribed online journals, you can also check a box to extend your search beyond the subscribed resources.

Key databases

Start with identifying the key databases covering your field by taking a look at the e-resources section on appropriate subject guide(s). Your Academic Liaison Librarian can also advise on the best ones to search.

Extending your search beyond Reading's databases

When looking at other systematic reviews you might identify useful databases which are not available at Reading (e.g. EMBASE). It may be possible to access these by visiting another library. For instance the British Library offers access to a range of databases however there are restrictions on downloading from these databases which will make adding the references to a reference manager very difficult. You will also need to register as a reader with them.

If you are unsure which databases to use, try looking at existing reviews in the same field for details of which databases they searched.

You may also wish to extend your search beyond the mainstream databases to ensure global coverage. The University of Leeds Library has put together a list of databases which may help:

Your Academic Liaison Librarian can offer further advice on accessing databases which are not part of our collection.

Hand-searching key journals

Once you have identified the key journals you may want to browse through their contents, or do a keyword search directly on the journal site, to make sure you haven't missed anything. Use BrowZine to access journals covered by Library subscriptions.

Using citations to identify other relevant studies

To supplement keyword searching for a comprehensive review, or for topics which are difficult to frame in a keyword search, take a look at the list of references at the end of any key articles to identify other possible studies. Some databases, such as Web of Science, Scopus and Google Scholar, allow you to track citations forward and identify papers that have cited a key paper since it was published. This gives an alternative way of identifying relevant studies which may not be retrieved by your keyword search. 

In addition to identifying published resources you will need a strategy for finding grey literature. This is usually research material that is not available via the usual published sources. This can include:

• conference papers/conference proceedings
• clinical trials
• government documents
• newsletters, fact sheets, bulletins, pamphlets
• reports
• surveys
• theses

These can be identified by running internet searches, and consulting key websites of relevant organisations.

Further guidance and sources