1. Bliss, C.K.: Semantography (Blissymbolics). Sydney Semantography Publications (1965)
2. Cooper, A.: About Face The Essential of User Interface Design. IDG Books (1995)
3. Lecture Notes in Computer Science;H. Cho,2007
4. Dhande, S., Roy, D.: Visual Representations for Learning: Doodle project (2002), http://www.media.mit.edu/cogmac/projects/doodle.html
5. Druin, A.: Cooperative Inquiry: Developing New Technology for Children with Children. In: Proceedings of ACM CHI 1999, pp. 592–599. ACM Press, New York (1999)