Papadopoulos, K. Charitakis, K. Koustriava, E. Kartasidou, L. Stylianidis, E. Kouroupetroglou, G. Sakalli Gumus, S. Müller, K. Yilmaz, E., Specification of symbols used in audio-tactile maps for individuals with blindness, Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), (9759), 160-167, 2016, Springer-Verlag,