F. Kummert, G. Fink, G. Sagerer, and E. Braun. Pattern Recognition, 1998. Proceedings. Fourteenth International
Conference on, 2, page 1165--1170 vol.2. (1998)
S. Braun, A. Schmidt, A. Walter, G. Nagypal, and V. Zacharias. Proceedings of the Workshop on Social and Collaborative Construction of Structured Knowledge at the 16th International World Wide Web Conference (WWW 07), Banff, Canada, (2007)