Designing a head-up game for children. - Koen Hendrix; Guo Yang; Dirk van de Mortel; Tim Tijs; Panos Markopoulos 001 (BCS HCI (1), 2008)

Increasing children's social competence through games, an exploratory study. - Koen Hendrix; Robert van Herk; Janneke Verhaegh; Panos Markopoulos 001 (IDC, 2009)