1. BSI 2002. BS EN 13724:2002 Postal services. Apertures of private letter boxes and letter plates. Requirements and test methods. BSL
2. Mechanisms and mechanical devices sourcebook.;Chironis,1996
3. Hirose, S. 2001. Super Meehano-System: New Perspective for Versatile Robotic System. In: RUS, D. & SINGH, S. (eds.) Experimental Robotics VII. Springer Berlin Heidelberg, pp.249-258.
4. HM Government. 2013. TheBuildingRegulations 2010, 2013 edition. Newcastle Upon Tyne: NBS.
5. Liu, J. et al. 2005. Analysis of stairs-climbing ability for a tracked reconfìgurable modular robot. Safety, Security and Rescue Robotics, Workshop, 2005 IEEE International, 6-9 June 2005, pp.36-41.