Belsley, D. A., Kuh, E., and Welsch, R. E. (1980), Regression Diagnostics: Identifying Influential Data and Sources of Collinearity, New York: John Wiley & Sons.

Rawlings, J. O., Pantula, S. G., and Dickey, D. A. (1998), Applied Regression Analysis: A Research Tool, 2nd Edition, New York: Springer-Verlag.

Sall, J. P. (1990), “Leverage Plots for General Linear Hypotheses,” American Statistician, 44, 308–315.