The Perspectiva of Peckham (13th century) became the established university textbook on perspective. It was the text Galileo likely used in his early studies of optics. Renaissance artists were well-versed in the classic works on perspective. For example, the Florentine sculptor Lorenzo Ghiberti cited an Italian translation of Ibn Al-Haytham as well as treatises by Witelo, Roger Bacon, and Peckham.