Books 2.17C

Revise second sentence to read:

Add the format (folio, quarto, octavo, duodecimo) to the dimensions.

Revise examples to read:

; 23 cm (quarto)

; 20 cm (octavo)

; 33 cm (folio)

; 23 cm (quarto)

1 sheet ; 48 x 27 cm