Centro Vasco de Arquitectura
Euskal Herriko Arkitektura Ikerkundea
http://www.oxforddnb.com/templates/article.jsp?articleid=31245&back=
http://thepeerage.com/p19141.htm
http://collage.cityoflondon.gov.uk/collage/app;jsessionid=375CC645F668F047304A869E689AF961?service=external/Item&sp=I18%3AHolford%2C+Sir+William%3A%3AH&sp=241502&sp=X