1. Celani, G.C., Milan, L.F.: Tactile scale models: three-dimensional info-graphics for space orientation of the blind and visually impaired. In: Virtual and Rapid Manufacturing: Advanced Research in Virtual and Rapid Prototyping, pp. 801–805. Taylor & Francis Group, London (2007)
2. Ciaffoni, G.: Ariadne GPS (Version 4.2.1) [Mobile application software] (2014).
https://itunes.apple.com/us/app/ariadne-gps/id441063072?mt=8
3. Edman, P.: Tactile Graphics. American Foundation for the Blind, New York (1992)
4. Image Searcher: TapTapSee (Version 2.1.8) [Mobile application software] (2014).
https://itunes.apple.com/us/app/taptapsee-blind-visually-impaired/id567635020?mt=8
5. Ina, S.: Computer graphics for the blind. ACM SIGCAPH Comput. Physically Handicapped 55, 16–23 (1996)