I have a PhD in astrophysics.
The Big Bang Theory Season 10, Episode 18
A PowerPoint presentation
by Sheldon Cooper, PhD."
The Big Bang Theory Season 3, Episode 15
If you could run out and get a PhD,
that might make her like you.
The Big Bang Theory Season 8, Episode 23
I must say, Amy, I was very impressed
to see that Bernadette got her PhD.
The Big Bang Theory Season 4, Episode 24
I have a PhD from Cornell University.
The Big Bang Theory Season 6, Episode 22