Dr. Darin M. Wood has written a helpful and well-documented essay on the structure(s) of Revelation (2006).
I noticed one or two minor mistakes. Wood ascribes the recapitulation theory to Joachim of Fiore and cites Wainwright, Mysterious Apocalypse, p. 51. However, according to Wainwright (p. 35), the recapitulation theory was used by Victorinus and formulated by Tyconius.
In notes 56 and 60, p. 18, and in note 67, p. 22 one could get the (erroneous) impression that Lambrecht and Beasley-Murray co-authored the article “A Structuration of Revelation 4:1-22:5,” but this is not the case (according to my notes, at least). Beasley-Murray was one of the contributors.