Finding who has cited articles that you found interesting can lead you to more current research on your topic that you did not find in your initial searches.
Science Citation Index database (aka Web of Science)
(1) Select the Cited Reference Search link to enter article information
(2) Select View Record and click the Times Cited link to get a full list of articles that cited this paper.
View a video demonstration (use the Back button to return to this page)
Google Scholar (http://scholar.google.com)
(1) Click on the Cited by link below a result in Google Scholar
(2) Browse the list of items that have cited this work
View a video demonstration (use the Back button to return to this page)
NOTE: Google Scholar may find more cited results because it includes not only articles, but also materials from conferences, books, associations, and dissertations. PubMed has only journal articles. Therefore, use Google Scholar as a complimentary resource to the other databases you have searched. This can make for a more comprehensive set of search results.