1. Breazeal, C., Scassellati, B. (1999). A context-dependent attention system for a social robot. In: Proceedings of sixth international joint conference on artificial intelligence (pp. 1146-1151).
2. Choi, Y., You, J., Oh, Y., et al. (2004). Automatic performance tuning of decentralized motion controllers for a small humanoid. In: The international conference on advanced mechatronics: Toward evolutionary fusion of IT and mechatronics: ICAM. The Japan Society of Mechanical Engineers (p. 46).
3. Head Gesture Recognition for the Moving Conversation Robot;Ejiri;The Technical Report of The Proceeding of The Institute of Electronics, Information and communication Engineers,2003
4. Principles of artificial neural networks (Advanced series in circuits and systems);Graupe,2007