General Editor, "The Medieval Franciscans" Series (E. J. Brill) (seven volumes to date on the themes the Friars and Jews, Dante and the Franciscan Tradition, Franciscan Art, and Franciscan Prayer)

“Francis and the Encounter with the Sultan,” in The Cambridge Companion to Francis of Assisi (Cambridge: University of Cambridge Press, 2012), 127-142.

“How the Spirit of Clare and Francis Continues to Influence Peace in Our World” Ecumenical Trends, Vol. 41, No. 1 (January 2012), 6-9.

“Roman Catholics and Bystanders during the Holocaust,” in Prism: An Interdisciplinary Journal for Holocaust Education (Volume 1, Issue 2, Spring 2010)

“The Death, Resurrection, and Ascension of Jesus in Medieval Christian Anti-Muslim Religious Polemics” in Islam and Muslim-Christian Relations, Vol. 21, 2 (April 2010), 157-173.

“Sharing the Wealth of Poverty: Franciscan Friars at the End of the Middle Ages” in Poverty and Prosperity: Franciscans and the Use of Money, (Washington Theological Union Symposium Papers, Vol. 9, 2009), ed. Daria Mitchell (Saint Bonaventure: The Franciscan Institute, 2009), 39-64.

“The Death and Resurrection Of Jesus In Medieval Christian And Jewish Polemical Literature” For Studies in Christian-Jewish Relations (Volume IV – 2009) (The Electronic Journal of the Council of Center of Center of Christian-Jewish Relations, Boston College)

Was Jesus of Nazareth the Messiah? Alphonso de Espina's Argument Against the Jews in the "Fortalitium Fidei" (c.1464) (Atlanta: Scholars Press, 1994) "The End of the World, Anti-Christ, and the Final Conversion of the Jews in the Fortalitium Fidei of Friar Alonso de Espina (d. 1464)" in Medieval Encounters: Jewish, Christian and Muslim Culture in Confluence and Dialogue, Vol. 12, No. 2 (2006), 224-273.

"Friar Alonso de Espina, Prayer, and Medieval Jewish, Muslim and Christian Polemical Literature" in Medieval Franciscan Prayer, Ed. Timothy Johnson (Leiden: E. J. Brill, 2006), 271-303.