Centro Vasco de Arquitectura
Euskal Herriko Arkitektura Ikerkundea
http://www.famous-people.info/287/Ralph-Thomas-Walker.html
http://landlordrocknyc.wordpress.com/tag/ralph-thomas-walker/
http://architectsandartisans.com/index.php/2012/08/ralph-walker-architect-of-the-century/