I have a PhD from Cornell University.
The Big Bang Theory Season 6, Episode 22
I'm getting my PhD.
The Big Bang Theory Season 4, Episode 24
I must say, Amy, I was very impressed
to see that Bernadette got her PhD.
The Big Bang Theory Season 4, Episode 24
A PowerPoint presentation
by Sheldon Cooper, PhD."
The Big Bang Theory Season 3, Episode 15
I have a PhD in astrophysics.
The Big Bang Theory Season 10, Episode 18