1. ND. Vaughan and JB. Gamble, “The modeling and simulation of a proportional solenoid valve,” J. of dyn. Syst. measurement and cont., Vol.118, No.1, pp. 120-125, 1996.
2. [2] F. Bu and B. Yao, “Adaptive robust precision motion control of single-rod hydraulic actuators with time-varying unknown inertia: a case study,” IMECE, Vol.6, pp. 131-138, 1999.
3. [3] T. Frankenfield and P. Stavrou, “Developing trends in hydraulics tied to electronic controls,” Control Eng., Vol.40, No.5, pp. 62-66, 1993.
4. [4] B. R. Andersen and J. L. Ayres, “Load sensing directional valves, current technology and future development,” The Fifth Scandinavian Int. Conf. on Fluid Power, Vol.1, pp. 99-119, 1997.
5. [5] M. E. MuNZER, “Control of mobile hydraulic cranes,” 1stFPNI-PhD Symp., pp. 475-483, 2000.