
Which is also called
The Hitchhiker's Guide to the Galaxy.
The Big Bang Theory Season 8, Episode 8

...so that he could write an entry about Earth
for The Hitchhiker's Guide to the Galaxy.
The Big Bang Theory Season 8, Episode 8

Wait. In The Hitchhikers Guide
to the Galaxy...
The Big Bang Theory Season 6, Episode 8

Yeah, see, if you just change the story
to the destruction of a GALAXY,
The Big Bang Theory Season 9, Episode 14

The Milky Way is a GALAXY in space.
The Big Bang Theory Season 6, Episode 5