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