Shiri Azenkot Sanjana Prasain Alan Borning Emily Fortuna Richard E. Ladner Jacob O. Wobbrock Enhancing independence and safety for blind and deaf-blind public transit riders. 3247-3256 2011 CHI http://doi.acm.org/10.1145/1978942.1979424 conf/chi/2011 db/conf/chi/chi2011.html#AzenkotPBFLW11