Centro Vasco de Arquitectura
Euskal Herriko Arkitektura Ikerkundea
http://www.engineering-timelines.com/scripts/engineeringItem.asp?id=474
http://en.wikipedia.org/wiki/Skerton_Bridge
http://www.francisfrith.com/lancaster/photos/from-skerton-bridge-1891_28599a/
http://www.bbc.co.uk/arts/yourpaintings/paintings/lancaster-from-the-river-with-skerton-bridge
http://colinpickering.blogspot.com.es/
http://www.flickr.com/photos/8291616@N08/1887372734/
http://www.geograph.org.uk/photo/2154737
http://glostransporthistory.visit-gloucestershire.co.uk/electrif.htm
http://commons.wikimedia.org/wiki/File:Skerton_Bridge.jpg
http://en.m.wikipedia.org/wiki/File:Skerton_Bridge,_Lancaster,_England_-_aedicula_detail.JPG