See also: https://www.catacombsociety.org/other-databases-of-digital-images/

Burnett, Andrew M. Coinage in the Roman World. London: Seaby, 1987.

Carradice, Ian A. and Theodore V. Buttrey. The Roman Imperial Coinage, vol. 2, pt. 1, Vespasian to Domitian, 2nd rev. ed. London: Spink, 2007.

Crawford, Michael H. Roman Republican Coinage, 2 vols. Cambridge: Cambridge University Press, 1983.

Harrison, James R., & L. L. Welborn, eds. The First Urban Churches 1: Methodological Foundations. Writings from the Greco-Roman world Supplement series, 7. Atlanta: SBL Press, 2015.

Hill, Philip. "Monuments of Ancient Rome as Coin Types," in The Numismatic Chronicle,143 (1983), 81-94.

Kent, John P. C. Roman Coins, rev. edition. London: Thames and Hudson, 1978.