Each course you're taking this semester may ask for a different citation style. If it's unclear on your assignment, ask your professor.
The good news is that the library can help you with any citation style. If you're not sure how to cite something properly, just stop by the Research Help Desk on the main floor, ask via online chat, or send an email to ask@gettysburg.edu. It can get confusing; we're happy to help!
Here are online guides for some of the most common citation styles. See the library's citation guide for more help, including links to the official style manuals and software to help with citations.