Citing (also called documenting or referencing) is giving credit to a source, usually in an in-text reference, note, or bibliography, depending on the style you are using (such as APA, MLA, Chicago, etc.). If you don’t know what style you should be using, ask your professor. There are clear guidelines showing how to document sources in the major styles in the “Writing, Style & Citation Guides” section of your subject’s library Research Guide. Close Window