1. K. Badenhausen, Manchester United tops the world’s 50 most valuable sports teams, Forbes, 16 July 2012.
2. On grouping for maximum homogeneity;Fisher;J. Amer. Statist. Assoc.,1958
3. Penalized regressions: the bridge versus the Lasso;Fu;J. Comput. Graph. Statist.,1998
4. Partition regression;Guthery;J. Amer. Statist. Assoc.,1974
5. J.A. Hartigan, Notes on clustering, Department of Statistics, Yale University, 1971.