Hitchhiker's Guide to the Galaxy books - a Spotter's Guide

How to recognise a Hitchhiker's Guide to the Galaxy book:

Here is one:





And here's another:





This is another one:





This one too:





And goodness gracious me, even this one:






But here is what a Hitchhiker' Guide to the Galaxy book does NOT look like:




So fuck YOU, Eoin Colfer, you smug Irish bastard.