Photo, 1959 International collaboration between artists and architects in the realisation of the new Gelsenkirchen Opera House
Photo, ca. 1960 Yves Klein and Rotraut with Ci-gît l'Espace [Here Lies Space] (RP 3) and the Sponge Relief (RE 20)
Photo, 1957 Yves Klein in front of his Sponge Sculpture at the exhibition "Monochrome Propositions of Yves Klein" Gallery One, London
Film, 1959 Yves Klein's exhibition : Bas-reliefs dans une forêt d'éponges [Bas-reliefs in a forest of sponges], galerie Iris Clert, Paris, France
Photo, 1959 Yves Klein, Iris Clert and Rotraut at the opening of the exhibition "Bas-reliefs in a sponge forest", Galerie Iris Clert