1. Nonlinear Programming;Avriel,2003
2. Symbolic Data Analysis;Billard,2006
3. Analysis of Symbolic Data. Exploratory Methods for Extracting Statistical Information from Complex Data,2000
4. Clustering algorithms and Kohonen maps for symbolic data;Bock;Journal of the Japanese Society of Computational Statistics,2002
5. Visualizing symbolic data by Kohonen maps;Bock,2008