Centro Vasco de Arquitectura
Euskal Herriko Arkitektura Ikerkundea
http://en.wikipedia.org/wiki/Basil_Spence
http://www.nationalgalleries.org/collection/artists-a-z/M/4228/artist_name/Lida%20Moser/record_id/3046
http://www.bbc.co.uk/programmes/b006qnmr/episodes/guide?page=75
http://www.historiccoventry.co.uk/cathedrals/spence.php