Bibliography - Wikipedia -- Fall Factor - Richard Goldstone -- The Standard Equation for Impact Force - UKClimbing.com -- Fall Factors Explained - UIAA -- Safety Standards - Ulrich Leuthäusser -- Physics of Climbing Ropes: Impact forces, fall factors and rope drag - Richard M. Leonard -- Belaying the Leader: An Omnibus on Climbing Safety (book) - Background pictures courtesy of Gil Manbar