I would cite your sources briefly within the presentation. This lends credibility to your talk.
Something like,
(lead-in to your comment/observation)
:"According to Dr. ___, Professor of Deviant Behavior at the University of Texas, writing in the Journal of Psychology just last month,...._____________________"
or
State your conclusion/comment, followed by a source citation.
"In the surveys I've conduced, 90 percent of students are terrified to get up and speak in front of class - any class," Phyllis Duggan shared with me last week when I interviewed her about speech apprehension. She's a Public Speaking professor at the University of Texas at Arlington."
Hope this is helpful.
Kate R.
I have to agree with Marie on one thing. A direct quote or graphic can easily be cited in the PPT. I would do that for sure. I was thinking of footnotes, which I would not put in the presentation.04/27/19