Photo, 1959 Yves Klein pronouncing his speech during the opening of the exhibition “Vision in Motion – Motion in Vision”
Photo, 1957 View of Yves Klein's "Aerostatic Sculpture" during his exhibition "Yves Klein: Propositions Monochromes", Galerie Iris Clert
Article, 1961, Roland F. Pease Jr. Testimonial of Roland F. Pease Jr. on the blue monochromes seen at the Leo Castelli exhibition, 1961