Electronic databases are the primary tools for finding research literature. The UH subject librarians could help you identify databases in your discipline.
Keywords and Subject-Term are two main methods for conducting searches in databases. We recommend combining both methods to improve the thoroughness of your literature search. To learn more about search strategies for systematic review, you may consult this series of Tutorials on Systematic Searches created by the librarians at the Yale University Medical Library. Here is a brief introduction of the two methods:
Subject Term (Subject Heading) Search:
Grey literature is often referring to literature that is not obtainable through normal publishing channels, or research published outside of commercial or academic publishing. It could include:
The citation tracking or snowballing method: This method allows you to widen your search by taking advantage of the references cited in a relevant article. There are two approaches to this. First, you can scour the reference sections of articles that you have already included in the review and pick up the ones that could be added to your list. Second, you can use certain citation tracking databases (i.e., Scopus and Web of Science) to identify articles that had subsequently cited papers that you have included in the review. The first approach works back in time from the article (backward tracking), whilst the second approach works forward in time from that article (forward tracking).
Hand searching: Handsearching is manually searching for articles or reports in selected journals, reports, or other types of relevant publications. This method would help identify articles missed from the electronic database searches due to insufficient database indexing or errors. It is a process of searching journal contents or reports page by page, cover to cover to identify the relevant studies.
Contact experts in the field could help you identify other or on-going studies they may be aware of but have missed by other literature search methods. This is a highly recommended step by serval organizations that support evidence-based research. As Petticrew & Roberts (2006) suggested in their book, Systematic Review in the Social Sciences, "Even if no additional studies are turned up by the experts, you will have greater confidence that you have identified all the relevant studies, and it also offers an opportunity to let other experts know that the review is underway."