1. Byloff FK, Darendeliler MA, Clar E, Darendeliler A. Distal molar movement using the pendulum appliance. Part 2: The effects of maxillary molar root uprighting bends. Angle Orthod. 1997; 67:261–270.
2. Wong AM, Rabie AB, Hägg U. The use of pendulum appliance in the treatment of Class II malocclusion. Br Dent J. 1999; 187:367–370.
Article
3. Worms FW, Isaacson RJ, Speidel TM. A concept and classification of centers of rotation and extraoral force systems. Angle Orthod. 1973; 43:384–401.