Photo, 1957 Yves Klein in front of his Sponge Sculpture at the exhibition "Monochrome Propositions of Yves Klein" Gallery One, London
Photo, january 14th 1961 Yves Klein surrounded by Sponge Sculptures during the exhibition "Monochrome und Feuer", Museum Haus Lange
Photo, 1959 Yves Klein, Iris Clert and Rotraut at the opening of the exhibition "Bas-reliefs in a sponge forest", Galerie Iris Clert