1. Fujita, M.: AIBO; towards the era of digital creatures. Int. J. of Robotics Research 20(10), 781–794 (2001)
2. Breazeal, C., Scassellati, B.: A context-dependent attention system for a social robot. In: Proc. Int. Joint Conf. on Artificial Intelligence, pp. 1146–1151 (1999)
3. Lecture Notes in Artificial Intelligence;H.G. Okuno,2002
4. Burgard, W., Cremers, A.B., Fox, D., Hahnel, D., Lakemeyer, G., Schulz, D., Steiner, W., Thrun, S.: The interactive museum tour-guide robot. In: Proc. of National Conference on Artificial Intelligence, pp. 11–18 (1998)
5. Moore, C., Dunham, P.J. (eds.): Joint Attention: Its Origins and Role in Development. Lawrence Erlbaum Associates, Mahwah (1995)