A.  De Luca, Flacco, F., Schiavi, R., and Bicchi, A., ?Nonlinear Decoupled Motion-Stiffness Control and Collision Detection/Reaction for the VSA-II Variable Stiffness Device?, in Proc. IEEE/RSJ International Conference on Intelligent RObots and Systems, St. Louis MO USA, 2009, pp. 5487-5494. 

A.  Bicchi, Lorussi, F., Murrieri, P., and Scordio, V. G., ?On The Problem of Simultaneous Localization, Map Building, and Servoing of Autonomous Vehicles?, in Advances in Control of Articulated and Mobile Robots, B.  Siciliano, De Luca, A., Melchiorri, C., and Casalino, G., Eds. Springer Verlag, 2004, pp. 223-239.