See Yoram Tsafrir, “The Location of the Seleucid Akra in Jerusalem,” in Jerusalem Revealed, ed. Yigael Yadin (Jerusalem: IES, 1975), pp. 85–86. More recently, Gregory J. Wightman, “Temple Fortresses in Jerusalem, Part 1: The Ptolemaic and Seleucid Areas,” Bulletin of Anglo-Israel Archaeological Society 9 (1989–1990), pp. 29–40.