1. K. Yoneda, Y. Ota, S. Hirose, Development of a hi-grip stair climbing crawler with hysteresis compliant blocs, in: International Conference on Climbing and Walking Robots, Karlsruhe, 2001, pp. 569–576.
2. Stairclimber of The Wheel Chair Lift Company. AYLESBURY Buckinghamshire HP18 9BA England, 2008. .
3. SunwaStair-Ship TRE-52, Sunwa CO. Ltd. Sendagaya, shiuya-ku, Tokyo Japan, 2008 .
4. TRACABOUT Personal Mobility vehicle. US Patent no 6250409, Trac About, Inc. Newton, KS 67114, USA. .
5. Development and practical application of a stairclimbing wheelchair in Nagasaki;Lawn;Journal of Human Friendly Welfare Robotic Systems,2001