CONSTANT (Nieuwenhuys). Constant – Amsterdam. Bochum: Stadtische Kunstgalerie, 1961. n.p. [72 p.]; ill.; 26 x 26 cm.; ill. black wrappers with text in grey.
Catalog of Constant’s exhibition at Stadtische Galerie in Bochum, held from March 4 to April 9, 1961. includes a list of 60 exhibited works, and an introductory essay on New Babylon by Constan (New Babylon: das experimentelle Denk-und Spielmodell/New Babylon: the experimental think and play model). Text in German.
A superb large format catalog. See https://stichtingconstant.nl/exhibition/constant-amsterdam