Arthur Koestler opened an exhibition in Galerie Mokum from works of art made by prisoners. January 11, 1969. Photo: Eric Koch / Anefo. (CC BY-SA 3.0). Collection: Nationaal Archief, Den Haag. Source: Wikimedia Commons.
Arthur Koestler opened an exhibition in Galerie Mokum from works of art made by prisoners. January 11, 1969. Photo: Eric Koch / Anefo. (CC BY-SA 3.0). Collection: Nationaal Archief, Den Haag. Source: Wikimedia Commons.