1. Angeles, J.: Fundamentals of Robotic Mechanical Systems: Theory, Methods, and Algorithms, 3rd edn. Springer, New York (2007). http://www.springer.com/engineering/robotics/book/978-0-387-29412-4
2. Angeles, J.: On the nature of the Cartesian stiffness matrix. Ing. Mec. 3, 163–170 (2010). Available, with its Corrigenda at http://revistasomim.net/revistas/3_5/art1.pdf
3. Ball, R.S.: Theory of Screws. Cambridge University Press, Cambridge (1998)
4. Davidason, J.K., Hunt, K.H.: Robots and Screw Theory: Applications of Kinematics and Statics to Robotics. Oxford University Press, London (2004). http://www.oupcanada.com/catalog/9780198562450.html
5. Ding, X., Selig, J.M.: On the compliance of coiled springs. Int. J. Mech. Sci. 46(5), 703–727 (2004). doi: 10.1016/j.ijmecsci.2004.05.009