
I challenge you to find a single REFERENCE
to Kryptonian skin cells.
The Big Bang Theory Season 1, Episode 2

Yeah, for future REFERENCE,
that's a while.
The Big Bang Theory Season 7, Episode 15

I marked the calendar
for future REFERENCE.
The Big Bang Theory Season 1, Episode 4

And for future REFERENCE,
it's this.
The Big Bang Theory Season 5, Episode 12

I'm surprised you know that REFERENCE.
The Big Bang Theory Season 8, Episode 19