Multivariate Convex Approximation and Least-Norm Convex Data-Smoothing. - Alex Y. D. Siem; Dick den Hertog; Aswin L. Hoffmann (ICCSA (3), 2006)

The correct Kriging variance estimated by bootstrapping. - Dick den Hertog; Jack P. C. Kleijnen; Alex Y. D. Siem (J. Oper. Res. Soc., 2006)

The effect of transformations on the approximation of univariate (convex) functions with applications to Pareto curves. - Alex Y. D. Siem; Dick den Hertog; Aswin L. Hoffmann (Eur. J. Oper. Res., 2008)

A Method for Approximating Univariate Convex Functions Using Only Function Value Evaluations. - Alex Y. D. Siem; Dick den Hertog; Aswin L. Hoffmann (INFORMS J. Comput., 2011)