Exhibition, 10 May 1957 - 25 May 1957 Yves Klein : Propositions monochromes Galerie Iris Clert, Paris, France
Exhibition, 31 May 1957 - 23 Jun 1957 Yves Propositions monochromes Galerie Schmela, Düsseldorf, Germany
Article, 1961, Roland F. Pease Jr. Testimonial of Roland F. Pease Jr. on the blue monochromes seen at the Leo Castelli exhibition, 1961