Manuel Castiñeiras. “Oxford Magdalen College, MS. Gr. 3: Artistic Practice, Byzantine Drawings and Mobility in Mediterranean Painting around 1200.” Arte medievale, IV serie - anno V (2015): pp. 87–100.

"Few drawings linked to pictorial practice survive from the 12th century. The innumerable cycles of wall paintings that once covered churches in the Mediterranean are not accompanied by sets of sketches or cartoons that act as guides or better enable us to understand the secrets of their artistic creation. Many scholars even discount the suggestion that models or copies were a part of Romanesque and Byzantine painting practice. In their opinion, 12th century painters used mnemotechnical methods – essentially visual memory triggered by oral instruction, in marked contrast to Renaissance practice. However, Magdalen College, Oxford MS. Gr. 3 has the capacity to dispel one’s doubts as to 11th or 2th-century model books."