was an obvious REFERENCE
The Big Bang Theory Season 7, Episode 3
I'm surprised you know that REFERENCE.
The Big Bang Theory Season 8, Episode 19
...you'd be in a non-inertial
REFERENCE frame and would...
The Big Bang Theory Season 1, Episode 3
Is that a REFERENCE
to my speech impediment?
The Big Bang Theory Season 7, Episode 10
...you might wanna skip the REFERENCE
to bowel movements.
The Big Bang Theory Season 1, Episode 1