1. Martins-Filho LS, Silvino JL, Resende P and Assunção TC (2003) Control of Robotic Leg Joints — Comparing PD and Sliding Mode Approaches. In: Muscato G and Longo D. (eds) Proc. CLAWAR’2003 — 6th Int. Conf. on Climbing and Walking Robots, Catania, Italy, 147–153.
2. Lee K-P, Koo T-W and Yoon Y-S (1998) Real-Time Dynamic Simulation of Quadruped Using Modified Velocity Transformation. In: Proc. of the IEEE Int. Conf. on Rob. and Aut. 1701–1706.
3. Song J, Low KH and Guo W (1999) A Simplified Hybrid Force/Position Controller Method for the Walking Robots. Robotica 17:583–589.
4. Silva MF, Machado JAT and Lopes AM (2003) Comparison of fractional and integer order control of an hexapod robot. In: Proc. VIB 2003 — ASME Int. 19th Biennial Conf. on Mech. Vib. and Noise, ASME, Chicago, Illinois, USA.
5. Silva MF, Machado JAT and Lopes AM (2003) Position / Force Control of a Walking Robot. MIROC-Machine Intelligence and Robotic Control 5:33–44.