If you are using one of the databases remember that the database will give you the exact citation for the article! Use your resources!
A citation...
describes a book, journal article, website, or other item
gives credit to the originator of an idea
enables the reader to access the cited item.
You must cite a source that you are using if you paraphrase or summarize any of the ideas given in the work AND if you use a direct quote from the resource (word-for-word). Citations are not just for word-for-word quotations; they must be used when you mention any ideas or information from a source.
MLA Handbook for Writers of Research Papers by Every discipline has their own citation style, however, every person/professor is different and they may have a preference for a different citation style, or prefer that you use an older format for citations. The books below are examples of the texts that can assist you with properly citing your sources.
Publication Manual of the American Psychological Association by 
The Chicago Manual of Style by