Smarter control variables: regression-adjusted linear and nonlinear controls. - Peter A. W. Lewis; Richard L. Ressler; R. Kevin Wood (WSC, 1987)

Variance reduction of quantile estimates via nonlinear control. - Peter A. W. Lewis; Richard L. Ressler (WSC, 1989)

Average regression-adjusted controlled regenerative estimates. - Peter A. W. Lewis; Richard L. Ressler (WSC, 1991)