Bootstrap. (s.f.). Getting started. Recuperado de http://getbootstrap.com/getting-started/

Bootstrap. (s.f.). CSS. Recuperado de http://getbootstrap.com/css/

Niederst Robbins, J. (2012). Learning Web Design. A Beginner's Guide to HTML, CSS, JavaScript, and Web Graphics. USA: O'Reilly Media.
Capítulo 15.