Centro Vasco de Arquitectura
Euskal Herriko Arkitektura Ikerkundea
Imagen tomada por Cristina Jiménez Manzano en 2013
http://soundlandscapes.files.wordpress.com/2010/08/img_03821.jpg
http://www.greatbuildings.com/cgi-bin/gbi.cgi/Paris_Metro_Entrances.html/cid_aj1693_b.html
http://www.greatbuildings.com/cgi-bin/gbi.cgi/Paris_Metro_Entrances.html/cid_3023122.html
http://www.greatbuildings.com/cgi-bin/gbc-drawing.cgi/Paris_Metro_Entrances.html/Paris_Metro_Section_A.jpg
http://www.greatbuildings.com/cgi-bin/gbc-drawing.cgi/Paris_Metro_Entrances.html/Paris_Metro_Front_Elev.jpg
http://www.greatbuildings.com/cgi-bin/gbc-drawing.cgi/Paris_Metro_Entrances.html/Paris_Metro_Entr._Plan.jpg
http://www.greatbuildings.com/cgi-bin/gbc-drawing.cgi/Paris_Metro_Entrances.html/Paris_Metro_Elev_C.jpg
http://www.greatbuildings.com/cgi-bin/gbc-drawing.cgi/Paris_Metro_Entrances.html/Paris_Metro_Elev_B.jpg
http://www.greatbuildings.com/cgi-bin/gbc-drawing.cgi/Paris_Metro_Entrances.html/Paris_Metro_Elev_A.jpg
http://www.greatbuildings.com/cgi-bin/gbi.cgi/Paris_Metro_Entrances.html/cid_aj1694_b.html
http://untappedcities.com/2013/11/19/nyc-v-paris-hector-guimard-art-nouveau-subway-entrances/