Document, 1955 Letter from Yves Klein to Jacques Tournier, author of the weekly "Les Nouvelles littéraires, artistiques et scientifiques".
Article, 1961, Roland F. Pease Jr. Testimonial of Roland F. Pease Jr. on the blue monochromes seen at the Leo Castelli exhibition, 1961
Document, 1959 Yves Klein, Text following the exhibition Motion in Vision / Vision in Motion, Hessenhuis
Document, 1958 Yves Klein, Account of the opening of the exhibition "Epoque pneumatique, la sensibilité picturale immatérielle à l'état matière première" at Galerie Iris Clert