R. Neßelrath. Proceedings of the 9th International Conference on Intelligent Environments (IE). International Conference on Intelligent Environments (IE-13), July 18-19, Athen, Greece, page 266-269. Washington, DC, USA, IEEE Computer Society, (2013)
D. Porta. Informatik 2010: Service Science - Neue Perspektiven für die Informatik, Beiträge der 40. Jahrestagung der Gesellschaft für Informatik e.V. (GI), Band 1, volume 175 of LNI, page 497-502. GI, (September 2010)
R. Nesselrath, and D. Porta. Proceedings of the 7th IJCAI Workshop on Knowledge and Reasoning in Practical Dialogue Systems (KRPDS-11), page 37-47. (July 2011)