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, 1958 Letter from Yves Klein to the President of the International Confederation of Atomic Explosions