Massimo Sorli Laura Gastaldi E. Codina S. de las Heras Dynamic analysis of pneumatic actuators. 589-602 1999 7 Simul. Pr. Theory 5-6 http://dx.doi.org/10.1016/S0928-4869(99)00012-9 db/journals/simpra/simpra7.html#SorliGCH99