Exhibition catalogue published in conjunction with show held at the Städtische Kunsthalle, Düsseldorf, January 21 - February 27, 1972. Traveled to the Haus am Waldsee Berlin, March 17 - April 30, 1972. Includes text by Le Parc and Jürgen Harten, Karl Ruhrberg, profuse illustrations of projects in black-and-white and color, project explanations, biography, and bibliography. Text in German.