"International Systems: Peace, Conflict Resolution, and Politics" (1975) by Kenneth Boulding (p. 375), as quoted in "Non-offensive defence for the twenty-first century" by Bjørn Møller, Håkan Wiberg, (p. 36), 1994.
Eric Ries (2011). “The Lean Startup: How Today's Entrepreneurs Use Continuous Innovation to Create Radically Successful Businesses”, p.20, Crown Business