This video will explain the cited reference search feature in Google Scholar. This feature allows you to start with one article that you think is relevant for your research, and see who else has cited it--it's a great way of finding other publications that might be relevant.
When you do a search in Google Scholar, you may see some results with a link that says "Cited by" and a number (that link will show up directly under an item's title). The number tells you how many other publications have cited that item, according to Google Scholar. If you click the link, you can see the list of publications that cite your result.
Let's take an example. Say I'm looking for information about the rhetoric of presidential speeches, and this article called "Presidential Rhetoric and the Public Agenda" seems pretty relevant. Right now, that article has a "cited by" link that shows 226 citing publications. If I click where it says "Cited by 226," I can see a list of what those publications are.
You can do another search to narrow down your results. Just choose the checkbox under the search bar that says "Search within articles citing" whatever your publication was called, and then search as normal. Going back to our example, for instance, we can narrow down our results to show only publications that cite "Presidential Rhetoric and the Public Agenda" (our original article) and that mention President Obama. If you want to get really specific with your search, you can even use the advanced search page the same way.
One thing to keep in mind is that the "cited by" option can only reveal publications that Google Scholar is aware of. But Google Scholar doesn't have access to all of the scholarly literature that exists. As a result, it might miss some publications that cite your item. To get the most comprehensive coverage, you should also try citation searching in another tool called Web of Science, a big interdisciplinary database covering the sciences, social sciences, and humanities. You can access Web of Science through the NCSU library's website.