H. Prendinger, T. Eichner, E. André, and M. Ishizuka. Advances in Computer Entertainment Technology, volume 203 of ACM International Conference Proceeding Series, page 87-90. ACM, (2007)
B. Endrass, H. Prendinger, E. André, and M. Ishizuka. 8th International conference on Intelligent Virtual Agents (IVA 2008), volume 5208 of LNCS, page 492-493. Springer, (2008)