Recently two more books arrived from Wipf and Stock on the topic for my masters thesis: spirituality for mission.
I've started reading the first of these: David J. Kettle 2012 Western culture in gospel context: theological bearings for mission and spirituality.
Sadly, Kettle who was the coordinator of the Gospel and Our Culture Network in Great Britain died last year. Already this book is a rare find: lucidly written, theologically astute and with profound insight. It is a masterful piece of missiology.