), University of Michigan Press, ISBN 0-472-06071-6*Kitzinger, Ernst, "Early Medieval Art at the British Museum", (1940) 2nd edn, 1955, British Museum*Lasko, Peter, "Ars Sacra, 800-1200", Penguin History of Art (now Yale), 1972 (nb, 1st edn.
), University of Michigan Press, ISBN 0-472-06071-6*Kitzinger, Ernst, "Early Medieval Art at the British Museum", (1940) 2nd edn, 1955, British Museum*Lasko, Peter, "Ars Sacra, 800-1200", Penguin History of Art (now Yale), 1972 (nb, 1st edn.