A citation search is a useful addition to the research process because it allows you to see what resources (articles, books / chapters, reports and so on) have cited a particular article that you think is useful - but that may, perhaps, be a little older than you'd like.
Google Scholar is particularly useful for doing citation searches (particular databases may tell you if the article has been cited by other articles but only if they're in that database. Scholar will look a bit wider than that.)
The file below takes you through doing a citation search.
