Use Citation Searching when you need to find newer articles that cite particular important, older works. Identifying these newer, citing references may be useful for a number of reasons:
Note, while older papers are often cited because the newer paper is building upon that earlier work, citations sometimes simply reflect the fact that the same methodology was used, possibly for a very different purpose.
Below are the major, multidisciplinary databases offering citation searching. Increasingly, other, subject-focused databases also offer this facility. Additionally, many databases provide the option to sort your results by "Times Cited" (or similar language). This sorting technique can help you identify the articles that are cited most heavily in a specific research area.