Jörg Schellmann, ed., Wall Works, Munich/New York, 1999, pp. 29-33
Jörg Schellmann, ed., Forty Are Better Than One, Munich/New York, 2009, pp. 58-59 and p. 400
Udo Kittelmann and Gabriele Knapstein, ed., Wall Works, Berlin, 2014, p. 143 (another example illustrated)