You should always give credit to your sources -- even in a PowerPoint presentation! Audiences may ask you about the information you present on a specific slide. Be prepared to match that information to a citation on your References slide.
APA Style does not offer specific advice on how to cite within PowerPoint presentations. Before using the suggestions below, check with your professor on specific citing requirements for your course assignments.
Suggestion 1: Include a complete list of References as the last slide of your presentation.
Suggestion 2: Include "Source lines" on individual slides and a complete References list at the end of the presentation.