Before you start searching for information to inform your research, think carefully about your research question, establish the key concepts and plan your search terms.
First, look at the title of your topic and try to identify the main keywords and concepts.
To carry out a thorough, effective search, try to come up with any synonyms, alternative or similar ways of referring to the keywords and concepts..
Are there any relevant acronyms or abbreviations?
Can any of the keywords be made plural?
Are there any narrower (more specific) or wider (more general) terms to consider?
Some words are spelt differently in American and UK English. There may also be some variations in terminology used in different cultures or countries.
Spending some time coming up with these alternative search terms will make your search more effective and improve your set of results.