Many databases contain a citation function. The following links are such examples. It is a handy way to get your citations done. However, it can only produce citations when your references are from a database. The citation function in a database is different from another. Furthermore, database generated citations can contain errors. You need to double check if these citations follow a particular style.
Example 1: citations generated from Sociological Abstracts
Example 2: Citing an article from an encyclopedia in Gale Virtual Reference Library. This example shows that the citation of the article can be found at the end of this article. The citation style is MLA. APA users should reformat the citation into APA style.