An Algorithm to Compute the Invariant Ring of a G_a-Action on an Affine Variety. - Arno van den Essen (J. Symb. Comput., 1993)

An algorithm to find a coordinate's mate. - Joost Berson; Arno van den Essen (J. Symb. Comput., 2003)

Multimagic Squares. - Harm Derksen; Christian Eggermont; Arno van den Essen (Am. Math. Mon., 2007)