Looking up citations is a useful strategy for finding information on a topic. Once you've found one relevant source, look for older research that the authors cited, and look for newer research that cites the given article.
As you find sources on your topic, look for patterns in what books, articles and other sources are repeatedly getting cited. These may be foundational sources crucial to understanding how scholars think about your topic.
"Diagram of the citation chain" by Bonnie Swoger.
Check footnotes and the list of cited sources at the end of an article, book or chapter. Try looking up the citations using the "Look Up a Citation" screen in the library catalog.
Some publisher websites highlight citations prominently as hyperlinks. When you find a source, you can easily link to the previous work cited in this source.
Look up a source in Google Scholar and use the "Cited by" feature to see other sources that have cited it. Only those sources indexed by Google Scholar are included in the count of citations.
Large research libraries subscribe to the ISI Web of Knowledge databases which compile comprehensive records on which sources have been cited by other sources.