Wildish, Mark: The Hieroglyphics of Horapollo Nilous: Hieroglyphic Semantics in Late Antiquity, s. 27. Issues in Ancient Philosophy. Routledge, 2017. ISBN 9781351376532. Teoksen verkkoversio.
Smith, William: ”Horapollo”, Dictionary of Greek and Roman Biography and Mythology. Boston: Little, Brown and Company, 1849–1867. Teoksen verkkoversio. (englanniksi)