1. Buja, A., Fowlkes, E. B., Keramidas, E. M., Kettenring, J. R., Lee, J. C., Swayne, D. F. and Tukey, P. A. “Discovering Features of Multivariate Data Through Statistical Graphics”. Proceedings of the Section on Statistical Graphics, American Statistical Association. pp.98–103.
2. Robust Locally Weighted Regression and Smoothing Scatterplots