Michelle P. Brown, Understanding Illuminated Manuscripts, revised: A Guide to Technical Terms, 2018, Getty Publications, ISBN1606065785, 9781606065785 p. 109.
Turner, Eric G. (2016). The Typology of the Early Codex. Philadelphia, Pa.: University of Pennsylvania Press. p.40. ISBN978-1-5128-0786-8. OCLC979970695.