Photo, ca. 1960 Yves Klein and Rotraut with Ci-gît l'Espace [Here Lies Space] (RP 3) and the Sponge Relief (RE 20)
Photo, 1959 International collaboration between artists and architects in the realisation of the new Gelsenkirchen Opera House
Photo, 1961 "Fire Fountain" during the exhibition "Yves Klein Monochrome und Feuer" at the Museum Haus Lange