Below are a few texts that (in varying degrees) touch upon the issue of the
filioque:
A. Edward Siecienski.
The Use of Maximus the Confessor's Writing on the Filioque at the Council of Ferrara-Florence (1438–1439). Ann Arbor, Michigan: UMI Dissertation Services, 2005.
Aristeides Papadakis.
Crisis in Byzantium: The Filioque Controversy in the Patriarchate of Gregory II of Cyprus (1283–1289). New York: Fordham University Press, 1983.
Aristeides Papadakis.
The Christian East and the Rise of the Papacy. Crestwood, NY: St. Vladimir's Seminary Press, 1994, pp. 232-238 and 379-408.
Richard Haugh.
Photius and the Carolingians: The Trinitarian Controversy. Belmont, MA: Nordland Publishing Company, 1975.
David Bradshaw.
Aristotle East and West: Metaphysics and the Division of Christendom. Cambridge: Cambridge University Press, 2004, pp. 214–220.
I have also posted a brief essay that I wrote on the filioque at my own website, click the link below if you wish to peruse it:
The Filioque Controversy