
...to inadequate serotonin PRODUCTION.
The Big Bang Theory Season 1, Episode 10

Those are PRODUCTION markings.
The Big Bang Theory Season 3, Episode 17

Yeah, they say the yeast in beer
helps with milk PRODUCTION.
The Big Bang Theory Season 10, Episode 22

The last big thing I did
was this PRODUCTION...
The Big Bang Theory Season 3, Episode 12

and a PRODUCTION of Anne Frank
above a bowling alley.
The Big Bang Theory Season 5, Episode 13