J. Breese, D. Heckerman, and C. Kadie. Proceedings of the Fourteenth conference on Uncertainty in artificial intelligence, page 43--52. Morgan Kaufmann Publishers Inc., (1998)
R. Yang, D. Gotz, J. Hensley, H. Towles, and M. Brown. VIS '01: Proceedings of the conference on Visualization '01, page 167--174. Washington, DC, USA, IEEE Computer Society, (2001)