Guide to Citing Research Sources: MLA Style or Guide to Citing Research Sources: APA Style - citation examples for sources such as books, articles, and online. NoodleTools(free registration required) - an online citation/bibliography composer for MLA or APA style. Zotero - a citation management tool, accessible through the Firefox web browser, which electronically captures bibliographic information and stores it for later citation. Research and Citation Resources from Purdue University's Online Writing Lab - additional guidance in citing online or print resources in MLA, APA, or other styles. The Basics of APA Style- an online tutorial provided by the American Psychological Association. Research and Documentation Online- provides more detailed information about citing online resources in several popular styles. Additional information is available in books on reserve at the library circulation desk, such as MLA Handbook for Writers of Research Papers and Publication Manual of the American Psychological Association.