A sumptuously produced, slipcased compilation of the ambulatory minimalist's letters to Yvon Lambert Andr? Cadere (1934-78) strove to remove art from the restrictions of museums and galleries. He is best known for his "Barres de bois rond" (round wooden bars), which he would carry to public spaces and exhibition openings. Between May 19 and July 3, 1978, Cadere wrote 43 letters to his friend, the gallerist Yvon Lambert, when...