Adriana Martín Alejandra Cechich Silvia E. Gordillo Gustavo Rossi A Three-Layered Approach to Model Web Accessibility for Blind Users. 76-83 2007 LA-WEB http://doi.ieeecomputersociety.org/10.1109/LA-WEB.2007.56 conf/la-web/2007 db/conf/la-web/la-web2007.html#MartinCGR07