F. Lehner, K. Schäfer, and M. Proksch. DeLFI 2003, Tagungsband der 1. e-Learning Fachtagung Informatik, 16.-18. September 2003 in Garching bei München., volume P-37 of Lecture Notes in Informatics, page 240-249. Bonn, GI, Gesellschaft für Informatik, Bonner Köllen Verlag, (2003)
A. Pashalidis, and C. Mitchell. Proceedings of 8th Australasian Conference on Information Security and Privacy (ACISP 2003), volume 2727 of Lecture Notes in Computer Science, page 249--264. Berlin Heidelberg, Springer-Verlag, (July 2003)
Y. Yang, J. Zhang, and B. Kisiel. Proc. of SIGIR-03and 26th ACM International Conference on Research and Development in Information Retrieval, page 96-103. ACM Press, (August 2003)