1. Communications in Computer and Information Science;R Lahtinen,2014
2. Parente, P., Bishop, G.: BATS: the blind audio tactile mapping system. In: Proceedings of the ACM Southeast Regional Conference, pp. 132–137 (2003)
3. Landau, B.: Early maps as an unlearned ability. Cognition 22, 201–223 (1986)
4. Thrower, N.: Maps and Civilization: Cartography in Society (245). University of Chicago Press, Chicago (1996)
5. Eriksson, Y.: Att känna bilder [To feel pictures], pp. 84–87. SIH Läromedel, Solna (1997)