If you want to view a list of sources that cite a particular article, you can do so by searching the original article in Web of Science or Scopus, both of which are available from the HS/HSL Databases list http://www.hshsl.umaryland.edu/resources/databases/index.cfm.

Once you have located the article in Web of Science, you will see Times Cited [number] listed to the right of the citation display. Click on the number to see the list of articles.

In Scopus, select the desired article citation from your search results then click the option View Cited by from the menu bar above.

Google Scholar also shows citing articles.  Under each citation in a Google Scholar results list, you will see a link that says, Cited by [number].  Click on the link to view the full list of citing articles. 

More information about finding citation counts and citing articles lists can be found on this page of the library's Research Impact Guide http://guides.hshsl.umaryland.edu/impact/article .