1. Fujiyoshi, M.: The Development of Plotting System That Enables People with Visual Disabilities to Produce Tactile Graphics. Technical Report of IEICE, WIT, vol. 103, No. 746 C7-12 (2004) (in Japanese)
2. Lecture Notes in Computer Science;A. Nishi,2006
3. Lecture Notes in Computer Science;I. Kopeček,2006
4. BES4 (in Japanese),
http://www.ttools.co.jp/product/eyes/BES4.html
5. EDEL-plus (in Japanese),
http://www7a.biglobe.ne.jp/~EDEL-plus/