Consult with your professor for the preferred style guide for your research paper or consult with your committee chair for the appropriate style guide for your thesis or dissertation. For journal or book manuscripts consult with the publisher. Some of the following links may provide useful information depending on your circumstances. ALSO, EndNote and RefWorks are two very versatile tools for collecting, managing and "automatically" creating in-text citations and bibliographies in any of up to 6,000 different output styles, e.g., APA, MLA, Chicago, Turabian, etc.
Watch this three minute UC Libraries video on why it is important to cite your sources.
University of Cincinnati Libraries
PO Box 210033 Cincinnati, Ohio 45221-0033