1. Descriptive statistics for symbolic data;Bertrand,2000
2. Dependencies and variation components of symbolic interval-valued data;Billard,2007
3. Billard, L., 2008. Sample covariance functions for complex quantitative data. In: Proceedings of the International Association of Statistical Computing Conference 2008, Yokohama, Japan.
4. From the statistics of data to the statistics of knowledge: symbolic data analysis;Billard;Journal of the American Statistical Association,2003
5. Symbolic Data Analysis: Conceptual Statistics and Data Mining;Billard,2006