"Use APA format" or "Follow MLA guidelines."
What does that mean?
The Modern Language Association (MLA), American Psychological Association (APA), and The University of Chicago Press issue guides to help students and researchers organize their papers and give credit to their sources. MLA style is used for English papers, APA style is used more often for social science papers, and Turabian is used mostly for history papers.
Always use the style your instructor asks for.
Include any special formatting he/she requires, even if it does not follow style guidelines.