“[Considering] this great variety of materials and uses that define books over some 5,000 years and in every part of the globe, … how adventurous can we be in attributing to material objects — from clay to digital tablets — the characteristics which make them books? … And as forms of print and print in conjunction with script and illustration increased in complexity, how catholic does our definition of ‘book’ become? Do we include maps and sheets of music, fold-out panoramas, and gathered-together illustrations and prints?” – Literary Hub