B. Jansen, D. Booth, and A. Spink. WWW '07: Proceedings of the 16th international conference on World Wide Web, page 1149--1150. New York, NY, USA, ACM, (2007)
J. Teevan, S. Dumais, and D. Liebling. SIGIR '08: Proceedings of the 31st annual international ACM SIGIR conference on Research and development in information retrieval, page 163--170. New York, NY, USA, ACM, (2008)
M. Strohmaier, P. Prettenhofer, and M. Lux. CSKGOI'08 International Workshop on Commonsense Knowledge and Goal Oriented Interfaces, in conjunction with IUI'08, Canary Islands, Spain, (2008)