Article, 1961, Roland F. Pease Jr. Testimonial of Roland F. Pease Jr. on the blue monochromes seen at the Leo Castelli exhibition, 1961
Artwork, 1962 Transfer of a Zone of Immaterial Pictorial Sensibility to Claude Pascal. Series n°1, Zone 06
Photo, january 1957 Yves Klein during the exhibition "Proposte monocrome, epoca blu", Galleria Apollinaire