333 Wacker Drive

1. Dupré, Judith (1996): Skyscrapers. Black Dog & Loventhal, New York (USA), pp. 80-81.
2. Dupré, Judith / Smith, Adrian (2008): Skyscrapers. A History of the World's Most Extraordinary Buildings. 2^nd edition, Black Dog & Leventhal Publishers, Inc., New York (USA), ISBN 978-1-57912-787-9, pp. 82-83.