The Hitchhiker's Quartet

From Author Wars - https://authorwars.com/books/the-hitchhikers-quartet-488001.html

Overview:

Title: The Hitchhiker's Quartet
Author: Douglas Adams
Year: 1986
Type: Omnibuses
Series: Hitchhiker's Guide to the Galaxy

Variant Titles:

1987. The More Than Complete Hitchhiker's Guide

Editions/Publications:

Unknown. The Hitchhiker's Quartet (Unknown, Douglas Adams, Harmony Books, ISBN-10: 0517564254, $19.95, 624 pages, Hardcover, Omnibus)