Anton S. Shiriaev Leonid B. Freidovich Anders Robertsson Rolf Johansson Anders Sandberg Virtual-Holonomic-Constraints-Based Design of Stable Oscillations of Furuta Pendulum: Theory and Experiments. 827-832 2007 23 IEEE Transactions on Robotics 4 http://dx.doi.org/10.1109/TRO.2007.900597 db/journals/trob/trob23.html#ShiriaevFRJS07