
But not so deep as to introduce
a new SOURCE of friction."
The Big Bang Theory Season 2, Episode 5

If this man had his own SOURCE
of product on this side of the border...
Breaking Bad Season 3, Episode 9

I know that money can
be a SOURCE of friction
The Big Bang Theory Season 12, Episode 3

as a SOURCE of information
The Big Bang Theory Season 11, Episode 16

Can you see the SOURCE code
that's generating the response?
Westworld Season 2, Episode 6