Shelfology Book Pairing

So Long, and Thanks for All the Fish
by Douglas Adams
The fourth madcap successor to The Hitchhiker's Guide to the Galaxy finds Arthur Dent and a giant robot aboard a UFO, headed for a distant star surrounded by souvenir booths to investigate something fishy. Reissue.
Published 2008
ISBN 9781439557617
Genre Trilogy of Four
&
The Restaurant at the End of the Universe
by Douglas Adams
The Restaurant at the End of the Universe continues the story of Arthur Dent; Trillian, his sometime girlfriend; Zaphod Beeblebrox, president of the Imperial Galactic Government; Marvin the depressed robot; and Ford, his longtime hitchhiking companion. The Heart of Gold is speeding away from Magrathea, the adventurers having barely escaped there with their lives at the end of The Hitchhiker's Guide to the Galaxy.
Published 2016
ISBN 9781535200080