Carr 2001, pp. 62–63. The garment only definitively became a veil in the 9th century. Carr, Annemarie Weyl (2001). "Threads of Authority: The Virgin Mary's Veil in the Middle Ages". In Stewart Gordon (ed.). Robes and Honor: The Medieval World of Investiture. Palgrave. pp. 59–94. doi:10.1007/978-1-349-61845-3. ISBN978-1-349-61847-7.