Belting, Hans, Likeness and Presence: A History of the Image Before the Era of Art, p. xxii, 1994, Chicago University Press (English trans.), ISBN 9780226042152, google books
jstor.org
The book was The Clash of Gods: A Reinterpretation of Early Christian Art by Thomas F. Mathews. Review by: W. Eugene Kleinbauer (quoted, from p. 937), Speculum, Vol. 70, No. 4 (Oct., 1995), pp. 937—941, Medieval Academy of America, JSTOR; JSTOR has other reviews, all with criticisms along similar lines: Peter Brown, The Art Bulletin, Vol. 77, No. 3 (Sep., 1995), pp. 499—502; RW. Eugene Kleinbauer, Speculum, Vol. 70, No. 4 (Oct., 1995), pp. 937—941, Liz James, The Burlington Magazine, Vol. 136, No. 1096 (Jul., 1994), pp. 458—459;Annabel Wharton, The American Historical Review, Vol. 100, No. 5 (Dec., 1995), pp. 1518—1519 .
newadvent.org
Marucchi, Orazio. «Archæology of the Cross and Crucifix.» The Catholic Encyclopedia. Vol. 4. New York: Robert Appleton Company, 1908. 7 Sept. 2018 online