1. Cynthia Breazeal, Brian Scassellati: Infant-like Social Interactions between a Robot and a Human Caretaker
2. Paul Ekman, Wallace V.Friesen: Facial Action Coding System, Consulting Psychologists Press Inc., 1978
3. Hiroshi Kobayashi, Fumio Hara: Real Time Dynamic Control of 6 Basic Facial Expressions on Face Robot, the Journal of the Robotics Society of Japan Vol. 14 No. 5, pp. 677–685, 1996
4. Kazutaka Mitobe, et al.: Consideration of Associated Movements of head and Eyes to optic and Acoustic Stimulation, The institute of electronics, information and communication engineers, Vol. 91, pp. 81–87, 1992
5. Atsuo Takanishi, et al.: Development of an Anthropomorphic Head-Eye Robot with Two Eyes, Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems, pp. 799–804, 1997