BÏF§ZF+18 Simultaneità e Chimismi lirici (BÏF§ZF+18. Simultaneity and Lyrical Chemistry) is a poetry book and artist's book published in 1915 by the Italian futurist Ardengo Soffici. Despite its rarity, the book has become famous as one of the finest examples of futurist 'words-in-freedom', and has been described as 'absolutely the most important book that came out of Florentine Futurism'. Originally printed in an edition of 300, the original book became even scarcer when the River Arno flooded in 1966, destroying many of the remaining copies.