D. Arthur, und S. Vassilvitskii. SODA '07: Proceedings of the eighteenth annual ACM-SIAM symposium on Discrete algorithms, Seite 1027--1035. Philadelphia, PA, USA, Society for Industrial and Applied Mathematics, (2007)
A. Hotho, A. Maedche, und S. Staab. ICDM '01: Proceedings of the 2001 IEEE International Conference on Data Mining, Seite 607--608. Washington, DC, USA, IEEE Computer Society, (2001)