Artist: Robert Morris Title: Observatory Earthwork-Project for Sonsbeek 71, Arnhem Year: 1971 Signed: No Medium: Offset Lithograph Paper Size: 20 x 29.75 inches ( 50.8 x 75.565 cm ) Image Size: 20 x 29.75 inches ( 50.8 x 75.565 cm ) Edition Size: 500 Framed: No Condition: A-: Near Mint, very light signs of handling Additional Details: Show held at the Tate Gallery from April 28-June 6th, 1971.