J. Mackinlay, R. Rao, and S. Card. Proceedings of the SIGCHI Conference on Human Factors in Computing Systems, page 67--73. New York, NY, USA, ACM Press/Addison-Wesley Publishing Co., (1995)
W. Theilmann, and K. Rothermel. Proc. 3rd International Workshop on Cooperative Information Agents (CIA'99), page 197--208. Uppsala, Sweden, Springer-Verlag: Heidelberg, Germany, (1999)
R. Jones, and K. Klinkner. CIKM '08: Proceeding of the 17th ACM conference on Information and knowledge management, page 699--708. New York, NY, USA, ACM, (2008)