1. Andrews, D.F., Bickel, P.J., Hampel, F.R., Huber, P.J., Rogers, W.H., Tukey, J.W.: Robust Estimates of Location: Survey and Advances. Princeton University Press, Princeton (1972)
2. Azzalini, A., Dalla Valle, A.: The multivariate skew-normal distribution. Biometrika 83, 715–726 (1996)
3. Chung, K.L.: A Course in Probability Theory, 2nd edn. Academic Press, New York (1974)
4. Courant, R., Hilbert, D.: Methods of Mathematical Physics, vol. 2. Wiley, New York (1962)
5. Dette, H., Neumeyer, N.: Nonparametric analysis of covariance. Ann. Stat. 29, 1361–1400 (2001)