Centro Vasco de Arquitectura
Euskal Herriko Arkitektura Ikerkundea
INTERNET http://en.wikipedia.org/wiki/Cirque_d%27%C3%A9t%C3%A9
INTERNET http://commons.wikimedia.org/wiki/Category:Cirque_d%27%C3%A9t%C3%A9
INTERNET http://circosphere.free.fr/ancien-cirque-champs-elysee.html
INTERNET http://www.artelista.com/grandes-maestros/obra/3461424188129983-festival-au-cirque-de-limperatrice-des-champs-elysees-champs-elysees-paris-1857-execution-de-lelie-oratorio-de-mendelssohn-in-le-monde-illustre-n36-du-26-decembre-1857.html
INTERNET http://www.architecture.com/LibraryDrawingsAndPhotographs/Exhibitionsandloans/IntheRing/CircusChamps.aspx#.UpDTduLBR8s