Exploratory data analysis in empirical research :  proceedings of the 25th Annual Conference of the Gesellschaft für Klassifikation e.V., University of Munich, March 14-16, 2001 / 
Manfred Schwaiger, Otto Opitz (eds.). 
 - Berlin ;  New York :  Springer,  c2003. 
 - xvi, 536 p. :  ill. ;  24 cm. 
 - Studies in classification, data analysis, and knowledge organization .