He's analogizing to the fictional "Hitchhiker's Guide to the Galaxy". There does exist an analog to the real world "Hitchhiker's Guide to the Galaxy": Carl E.

He's analogizing to the fictional "Hitchhiker's Guide to the Galaxy". There does exist an analog to the real world "Hitchhiker's Guide to the Galaxy": Carl E. Linderholm's "Mathematics Made Difficult". Utterly hilarious. Regrettably, it's out of print, and you have a choice of paying upwards of $138.50 (abebooks.com) for a used copy of a book of jokes, or finding the pirated pdf I once encountered in a search (I've no idea how complete that was).