43. The exact duration of the exhibition at the Vrije Academie is not entirely clear. Different sources give various closing dates. The catalogue states: ‘La Haye, Vrije Academie du 25 mai au 20 juin 1957’; the invitation: ‘duur van de tentoonstelling: van 25 mei t/m 1 juli 1957’; and the poster: ’25 mei – 6 juli’.