There are many applications available to help you create citations. Some databases also provide citation formatting assistance. These can be convenient, but they are NOT 100% accurate. ALWAYS check that the citation is formatted correctly according to the official style guide.
The following are all free citation generators:
KnightCite Citation Service from the Hekman Library of Calvin College in Grand Rapids, Michigan.
Son of Citation Machine from Landmarks for Schools.
Zotero from Roy Rosenzweig Center for History and New Media.
Cite Fast includes APA, MLA, and Chicago