Y. Yesilada, G. Brajnik, M. Vigo, and S. Harper. Proceedings of the International Cross-Disciplinary Conference on Web Accessibility, page 19:1--19:9. New York, NY, USA, ACM, (2012)
G. Mbipom, and S. Harper. The proceedings of the 13th international ACM SIGACCESS conference on Computers and accessibility, page 147--154. New York, NY, USA, ACM, (October 2011)