1. Braaten, Carl E., and Jenson, Robert W. (2003). One Body through the Cross: The Princeton Proposal for Christian Unity, Wm. B. Eerdmans Publishing Co.
2. Gunton, Colin (2005). The One, the Three and the Many: God, Creation and the Culture of Modernity, Cambridge University Press.
3. Harmon, Steven R. (2006). Towards Baptist Catholicity: Essays on Tradition and the Baptist Vision, Wipf & Stock.
4. International Theological Commission (2018). Synodality in the Life and Mission of the Church, Vatican.
5. Murray, Paul D. (2008). Receptive Ecumenism and the Call to Catholic Learning: Exploring a Way for Contemporary Ecumenism, Oxford University Press.