Dirk Gently's Holistic Detective Agency
The Salmon of Doubt: Hitchhiking the Galaxy One Last Time (Dirk Gently Book 3)
And Another Thing... (Hitchhiker's Guide to the Galaxy Book 6)
Mostly Harmless (Hitchhiker's Guide to the Galaxy Book 5)
So Long, and Thanks for All the Fish (Hitchhiker's Guide to the Galaxy Book 4)
Life, the Universe and Everything (Hitchhiker's Guide to the Galaxy Book 3)
The Ultimate Hitchhiker's Guide to the Galaxy: Five Novels in One Outrageous Volume
The Restaurant at the End of the Universe (Hitchhiker's Guide to the Galaxy Book 2)
Dirk Gently's Holistic Detective Agency Box Set: Dirk Gently's Holistic Detective Agency and The Long Dark Tea-Time of the Soul