The Ultimate Hitchhiker's Guide to the Galaxy

From Author Wars - https://authorwars.com/publications/the-ultimate-hitchhikers-guide-to-the-galaxy-904403.html

Overview:

Title: The Ultimate Hitchhiker's Guide to the Galaxy
Author: Douglas Adams
Year: Unknown
ISBN-10: 9781509886517
Publisher: Pan Books
Price: £12.99
Binding: ebook
Type: Omnibus
Title Reference: Mostly Harmless
Notes: Data from Amazon UK, Kobo (GB) and publisher's site between 2022-06-11 and 2022-06-30. Product listings at all of the aforementioned sites give a publication date of 2017-11-30. However the cover of this ebook (as of June 2022) states that this is a "42[nd] anniversary edition", which would date it to some time in 2021. A paperback edition with the same cover has a publication date of 2020-10-01 according to the publisher's site. Print length of 832 pages listed by publisher's site; 747 pages listed by Amazon UK. Subtitled "A Trilogy in Five Parts" on the title page (per Amazon's "Look Inside" preview) and the Amazon UK product listing. Earlier Amazon listings circa March 2020 had the subtitle "A Trilogy in Four Parts", but this seems to be an error - rather than an indication of content changes - as (a) the reported page count is/was 747 pages for both listings, and (b) the earlier listing has a different cover image which states "The Complete Trilogy of Five".