1. BOCK, H.-H. and DIDAY, E. (2000): Analysis of Symbolic Data, Exploratory methods for extracting statistical information from complex data. Springer-Verlag, Berlin-Heidelberg.
2. BRITO, P. (1991): Analyse de Données Symboliques. Pyramides d’Héritage. PhD Thesis, Mathématiques de la Décision, Univ. Paris-IX Dauphine.
3. BRITO, P. (1994): Use of pyramids in symbolic data analysis. In: E. Diday, et al. (Eds.): New Approaches in Classification and Data Analysis. Springer-Verlag, Berlin-Heidelberg, 378–386.
4. BRITO, P. (1998): Symbolic clustering of probabilistic data. In: A. Rizzi, M. Vichi and H.-H. Bock (Eds.): Advances in Data Science and Classification. Springer, Berlin, 185–190.
5. BRITO, P. and DE CARVALHO, F.A.T. (1999): Symbolic clustering in the presence of hierarchical rules. In: Studies and Research, Proceedings of the Conference on Knowledge Extraction and Symbolic Data Analysis (KESDA’98). Office for Official Publications of the European Communities, Luxembourg, 119–128.