Verslag studiedag Nederlandse equipe, Europese Unie van Christen-democraten, Scheveningen, 3 mai 1968, La Haye, 1968 (55 p.).
Possibilities and boundaries to Dutch external policies] (with others), Verslag studiedag Nederlandse equipe, Europese Unie van Christen-democraten, Scheveningen, 3 May 1968, The Hague, 1968 (55 pp.).