Centro Vasco de Arquitectura
Euskal Herriko Arkitektura Ikerkundea
http://commons.wikimedia.org/wiki/File:D%C3%BCsseldorf_-_Mannesmannufer_-_Mannesmann-Haus_01_ies.jpg
http://www.skyscrapercity.com/showthread.php?t=584411&page=372&langid=5
http://commons.wikimedia.org/wiki/File:Behrens_d%C3%BCsseld_vodafon_ehem_mannesmann_vorderseite01.jpg
4. http://commons.wikimedia.org/wiki/File:Behrens_d%C3%BCsseld_vodafon_ehem_mannesmann_vordereingang.jpg