C. Bauer, M. Schedl, V. Angerer, and S. Wegenkittl. Proceedings of the 27th ACM International Conference on Multimedia, page 1044-1046. Nice, france, ACM, (October 2019)
S. Hartley, M. Cavazza, J. Lugrin, and M. Le Bras. Proceedings of the 18th Workshop on Qualitative Reasoning, Evanston, Illinois, USA, Northwestern University, (August 2004)
D. Sonntag, and P. Heim. KI 2007: Advances in Artificial Intelligence, volume 4667 of Lecture Notes in Computer Science, page 506-509. Berlin, Heidelberg, Springer, (2007)