E. Wilde, S. Anand, and P. Zimmermann. Research and Advanced Technology for Digital Libraries, 9th European Conference, ECDL 2005, Vienna, Austria, September 18-23, 2005, Proceedings, volume 3652 of Lecture Notes in Computer Science, page 479--480. Springer, (2005)
J. Freyne, R. Farzan, P. Brusilovsky, B. Smyth, and M. Coyle. IUI '07: Proceedings of the 12th international conference on Intelligent user interfaces, page 52--61. New York, NY, USA, ACM Press, (2007)
R. Farzan, and P. Brusilovsky. HT '08: Proceedings of the nineteenth ACM conference on Hypertext and hypermedia, page 203--212. New York, NY, USA, ACM, (2008)