Books:
Cassiodorus, St. Gregory the Great, and Anonymous Greek Scholia. Writings on the Apocalypse.
Pseudo-Cyril of Alexandria. Commentary on the Apocalypse
Tyconius: Exposition of the Apocalypse
Early Latin Commentaries on the Apocalypse
Carolingian Commentaries on the Apocalypse by Theodulf and Smaragdus
The Seven Seals of the Apocalypse
Revelation and the First Century
Articles:
“Exegesis of the Apocalypse in the Tenth Century” was recently published as Chapter 8 in the Cambridge Companion to Apocalyptic Literature edited by Colin McAllister.
“Antipas in Early Commentaries” is available in the book: The Rapture and the Fig Tree Generation by Gary DeMar