1. Barnett, V., Lewis, T., 1984. Outliers in Statistical Data, 2nd ed. Wiley, New York.
2. Robust procedures in multivariate analysis I: robust covariance estimation.;Campbell;Ann. Statist.,1980
3. Coleman, J., 1966. Equality of Educational Opportunity, two volumes. Office of Education, U.C., Department of Health, Washington, D.C.
4. Cook, R.D., Weisberg, S., 1982. Residual and Influence in Regression. Chapman and Hall, New York.
5. Exact iterative computation of the robust multivariate minimum volume ellipsoid estimator;Cook;Statist. Probab. Lett.,1993