In beamer (presentation), I had seen example of insertion of a remark/small point during the presentation as below.
There, the author speaks (during presentation) as follows
"Consider the base case, namely when M/N is simple ... this work is done by Kleidmann, Liebeck,etc."
And while speaking this, he points out the names of Methematicians specifically as pointed below in slide.
Q. What are the commands to insert such pointing remarks, notes during slide presentation? (Please insert appropriate tag if necessary, since I do not have much idea of it.)