Document, 1961 Invitation card for the exhibition "Yves Klein Monochrome und Feuer" at the Museum Haus Lange in Krefeld
Document, 1964 Invitation card for the exhibition "Yves Klein Peintures de feu" at the Galerie Schmela, Düsseldorf
Document, 1958 Invitation card for the exhibition "Vitesse pure et stabilité monochrome" at galerie Iris Clert