(1) S. Nirose, S. Aoki and J. Miyake, TorrainAdaptive Quadru-Track Vehicle HELIOS-II Proc.of tne 20th International Symposium on Industrial Robots (1989), 235.
(2) M.H.Raibert, H.B. Brown Jr.and M. Cheppon,Experimonts in Balances witb 3D Ono-LeggedHopping Machine, Intern. Journal of RoboticsResearch, MIT Press, 3-2 (1984), 75.
(3) M. H. Raibort, Legged Robots That Balance,MIT Press (1986).