You are familiar with the concept of citations. You may have chased down a few interesting citations from a book or article to find more material on your subject. In doing this, you are looking for the sources the author of the book or article used, so you are only going to find older material.
There is another way of using citations. Let's say you have had trouble finding really good sources for your paper, but at last you've found one great article that is spot on for your topic. You can follow citations forward as well as backward!
Let's say you want to write about how the music people play and listen to in cars is important to their identity. Eventually you find a journal article that discusses this and touches on lowrider culture: LaBelle, Brandon. "Pump up the bass--rhythm, cars, and auditory scaffolding." The Senses and Society, vol. 3, no. 2, 2008, p. 187-203. A savvy researcher
But most of what you've found this way predates LaBelle's article. And a lot of it doesn't deal with cars specifically. Another way you can search is to paste the title of the article into the Primo search space:
The article will be shown in the result list and will have a button for finding Sources Citing This. Clicking the Citing This button will show a list of some articles that have used LaBelle's, including "Acoustic Cocooning: How the Car became a Place to Unwind." Each article in the list has its own Sources Citing This button, so you can continue to follow a chain of articles.
Not all the articles that are in the cited-by trail are necessarily found in Primo. You can use Google Scholar to search for more.
Beneath each entry in Google Scholar is a line of links, including Cited by. Clicking the Cited by link will bring up a new list of articles that used the original article.