G. M.  Gasparri, Garabini, M., Pallottino, L., Malagia, L., Catalano, M. G., Grioli, G., and Bicchi, A., ?Variable Stiffness Control for Oscillation Damping?, in IEEE International Conference of Intelligent Robots and Systems (IROS2015), Hamburg, Germany, September 28 - October 02, 2015, 2015, pp. 6543 - 6550 [Online]. Available: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7354312