Centro Vasco de Arquitectura
Euskal Herriko Arkitektura Ikerkundea
http://upload.wikimedia.org/wikipedia/commons/8/85/Picture_of_Charles_Follen_McKim.jpg
http://upload.wikimedia.org/wikipedia/commons/d/d4/Charles_Follen_McKim_by_Frances_Benjamin_Johnston.jpg
http://global.britannica.com/EBchecked/topic/354929/Charles-Follen-McKim
https://global.britannica.com/biography/Charles-Follen-McKim