Giving oral citations are just like narrative citations in an essay.
- The first time you cite someone, introduce them. It's not "According to Jane Doe" but "According to Harvard psychologist, Jane Doe, who led a study on..."
- Is the source important? Consider namedropping them. Is the source a random news article, helpful but not groundbreaking? Leave it parenthetical -- seen but not mentioned.
- You should have both citations on the slide, a bibliography at the end, and your oral citations -- all three. The oral citations should reflect your bibliography, and they don't necessarily replace your on-slide credits.