Multi-Robot Motion Planning of k-Colored Discs Is PSPACE-Hard. - Thomas Brocken; G. Wessel van der Heijden; Irina Kostitsyna; Lloyd E. Lo-Wong; Remco J. A. Surtel (FUN, 2021)

Online busy time scheduling with flexible jobs. - Susanne Albers; G. Wessel van der Heijden (CoRR, 2024)