http://moon.es/uhf/responsive-web-design-en-clinicseo-44/
http://moon.es/uhf/imagenes-en-el-responsive-web-design-19/
http://adaptive-images.com/
http://www.webpagetest.org/
http://www.webpagetest.org/
http://googlewebmastercentral.blogspot.com.es/2012/04/responsive-design-harnessing-power-of.html