Louis Flynn, Joost Geeroms, Rene Jimenez-Fabian, Bram Vanderborght, Nicola Vitiello, Dirk Lefeber. Ankle-knee prosthesis with active ankle and energy transfer: Development of the CYBERLEGs Alpha-Prosthesis. Robotics and Autonomous Systems, 73:4-15, 2015. [doi]