1. Barker, H. Gaylon. 2015. The Cross of Reality: Luther’s Theologia Crucis and Bonhoeffer’s Christology. Minneapolis: Fortress.
2. Bonhoeffer, Dietrich. 1948. The Cost of Discipleship. London: SCM Press.
3. ———. 1973. Letters and Papers from Prison. London: SCM Press.
4. Feil, Ernst. 1985. The Theology of Dietrich Bonhoeffer. Philadelphia: Fortress Press.
5. Graham, Elaine, and Stephen L. Lowe. 2009. What Makes a Good City? Public Theology and Urban Church. London: Darton Longman Todd.