What others have said, based on this book
Staff talk on becoming a movement - Tim Keller (video)
Movement Dynamics - Tim Keller (pdf)
Changing The City With The Gospel Takes A Movement - Tim Keller (The Gospel Coalition)
Gospel Eco-Systems - Tim Keller
Movement Dynamics - Tim Keller (requires subscription)
Ministry Movements – Tim Keller
These videos are an introduction to Alan Hirsch's book, The Forgotten Ways
Ecclesia: An Institution Or Movement? - Derek Wilder (Lives Transforming)
How Movements And Institutions Contrast - Tim Keller