"Richard Hefter and Martin Stephen Moskof’s Shufflebook (1971), ostensibly a juvenile composed of a pack of cards, one side of which contains “and the [name of an animal],” while the other side has just verbs. The sequence of possible combinations is nearly infinite, and merely for approaching that concept in a book of fiction Shufflebook, notwithstanding its slick and trivial contents, is valuable." (Source: Neglected Books, https://neglectedbooks.com/?p=6448)