1. Follow the format your professor suggests.
2. Ask your professor what to use if no format was assigned.
3. If you have no advice from your professor, try these:
Humanities (especially literature or languages): MLA (Modern Language Association)
Social sciences (especially psychology and behavioral science): APA (American Psychological Association)
Physical and natural sciences: CSE (Council of Scientific Editors)
General: Turabian is used by students in all disciplines. It is designed to complement the Chicago Manual of Style, but is simpler and easier to use.
Chicago Manual of Style: Chicago is used by scholarly writers in all disciplines. It contains two separate styles: one for writers in literature, history and the arts, and one for writers in the physical, natural and social sciences.