Verse-by-Verse Commentaries:

Joyce G. Baldwin, Haggai, Zechariah, Malachi (Tyndale), Inter-Varsity, 1972.
Charles L. Feinberg, "Zechariah" in The Wycliffe Bible Commentary, The Southwestern Company, 1968: 897-911.

Monographs, Compilations, and Studies:

Mike Butterworth, The Structure and the Book of Zechariah (JSOT Supplement, 130), Scholars Press, 1988.
Charles L. Feinberg, God Remembers: Studies in Zechariah, Van Kampen Press, 1950.
Meredith G. Kline, Glory in our Midst: A Biblical-Theological Reading of Zechariah's Night Visions, Two-Age Press, 2000.*****

Articles and Essays:

David J. Clark, "Discourse Structure in Zechariah 7:1-8:23," Bible Translator 36.3 (1985) :328-335.
James A. Hartle, "The Literary Unity of Zechariah," JETS 35 (1992): 145-157.
Meredith G. Kline
, "The Structure Of The Book Of Zechariah " JETS, 34 (1991), 179-193. ****

More Commentaries:

Elizabeth Achtemeier, Nahum-Malachi (Interpretation), Westminster John Knox, 1986.
David W. Baker, Nahum, Habakkuk, Zephaniah (Tyndale), Inter-Varsity, 1988.
Walter Kaiser, Micah, Nahum, Habakkuk, Zephaniah, Haggai, Zechariah, Malachi (Mastering the Old Testament), Word Books, 1992.
J. L. Mackay, Haggai, Zechariah & Malachi (Focus on the Bible), Christian Focus, 1994.
Thomas E. McComiskey, "Zechariah" in The Minor Prophets, Vol. III (ed. T. McComiskey), Baker, 1998.
Carol L. and Eric M. Meyers, Haggai and Zechariah 1-8 (Anchor), Doubleday, 1987.
Ben C. Ollenburger, "Zechariah" in The New Interpreter's Bible, vol. VII, Abingdon, 1996.
J. J. Roberts, Nahum, Habakkuk, and Zephaniah (OTL), Westminster/ John Knox, 1991.
Ralph L Smith, Micah-Malachi, (Word Biblical Commentary, 32), Word Books, 1984.

More Monographs

More Articles:

Charles Lee Feinberg, "Exegetical Studies in Zechariah," BSac 97 (1940): 189-199; 318-324; 435-447; 98 (1941); 56-68; 169-182. (six parts)