Centro Vasco de Arquitectura
Euskal Herriko Arkitektura Ikerkundea
http://www.puentemania.com/743
http://commons.wikimedia.org/wiki/File:Britannia_Bridge_lion.jpg
http://commons.wikimedia.org/wiki/File:Conference_of_Engineers_at_the_Menai_Straits_Preparatory_to_Floating_one_of_the_Tubes_of_the_Britannia_Bridge_by_John_Lucas.jpg
http://commons.wikimedia.org/wiki/File:Britannia_Bridge_wrought_iron_section.jpg
http://commons.wikimedia.org/wiki/File:Britanniabruecke_Postkarte.jpg
http://commons.wikimedia.org/wiki/File:Britannia_Bridge_-_circa_1852.jpg
http://commons.wikimedia.org/wiki/File:Brittania_Bridge_Train_crossing_3.JPG
http://nisee.berkeley.edu/elibrary/getpkg?id=GoddenA40-50
https://www.pinterest.com/pin/571042427722451467/
http://www.kosmoid.net/technology/bouch
http://www.2d53.co.uk/britanniabridge/Fire%20Report%20Pictures.htm
http://www.victorianweb.org/periodicals/iln/16.html
http://menaibridges.co.uk/bbhistory.php
http://www.old-print.com/mas_assets/full2/P1140849/P1140849025.jpg