Demetriou IC. L2CXCV: A FORTRAN 77 package for least squares convex / concave data smoothing. Computer Physics Communications (CPC). 2006;Vol. 174:643-668.

Demetriou IC, Lipitakis EA, Vassiliou EE. Efficient use of Toeplitz matrices for least squares data fitting by nonnegative differences. HERMIS-$\mu\pi$ Intl. Journal. 2006;Vol. 6:135-153.

Demetriou IC, Papakonstantinou SS. Discrete L1 Linear Spline Approximation (Contribution to the memory of Professor D.J. Evans). Journal of Neural Parallel and Scientific Computations (NPSC). 2006;14:157-178.

Vassiliou EE, Demetriou IC. A test of significance of successive m-convex regressions (Έλεγχος Σημαντικότητας Διαδοχικών m-Κυρτών Παλινδρομήσεων). In: Proceedings of the 19th Hellenic Conference on Statistics, Greek Statistical Institute. ; 2006. pp. 135-146.

Demetriou IC, Georgiadou SA. The Karush-Kuhn-Tucker statistics for testing data convexity and an application to infant mortality against GDP (Το Στατιστικό Karush-Kuhn-Tucker για τον Έλεγχο Κυρτότητας Δεδομένων και μια Εφαρμογή στην Παιδική Θνησιμότητα ως προς ΑΕΠ). In: Proceedings of the 19th Hellenic Conference on Statistics, Greek Statistical Institute. Vol. 2006. ; 2006. pp. 155-163.