N. Bikakis, G. Giannopoulos, T. Dalamagas, and T. Sellis. Proceedings of the 2010 international conference on On the move to meaningful internet systems: Part II, page 921--938. Berlin, Heidelberg, Springer-Verlag, (2010)
J. Kahan, and M. Koivunen. WWW '01: Proceedings of the 10th international conference on World Wide Web, page 623--632. New York, NY, USA, ACM Press, (2001)