First things first. What citation style is your professor asking for?
The most common styles are MLA, Chicago Style, and APA. Each one has an in-depth style guide that you may want to take a look at (see Official Style guides box below).
MLA is commonly used in the humanities, such as English. Chicago Style is a popular choice for history and law. APA is used mostly in the social sciences. Here at the business school, most professors want either APA or Chicago. When in doubt, just ask your instructor!
See more for each style: