Interested in Bonhoeffer's Poetry? Here's a great book on the poems, edited by Bernd Wannenwetsch:
http://www.amazon.com/Who-Bonhoeffers-Theology-through-Poetry/dp/0567067831/ref=sr_1_1?ie=UTF8&qid=1391030702&sr=8-1&keywords=wannenwetsch+who+am+i
