↑ Biblioteca Apostolica Vaticana, Pal. lat. 50, and Alba Iulia, Biblioteca Documenta Batthyaneum, s.n.
↑ Illustration; Herbert Schultz, p. 283, The Carolingians in Central Europe, their history, arts, and architecture: a cultural history of Central Europe, 750-900, BRILL, 2004, ISBN 9004131493, 9789004131491
