מקס ורטהיימר – הבדלי גרסאות

* Cherry, K. (n.d.). Perceptual Organization - Gestalt Laws of Perceptual Organization. Psychology - Complete Guide to Psychology for Students, Educators & Enthusiasts. Retrieved February 25, 2012

* Hothersall, D. (2003). History of Psychology. New York: McGraw-Hill.