M. Hassan J, A. Taha AW, A. Oleiwi M. Linear Analysis to Control an Electro-hydraulic System Using Proportional Directional Control Valve. J. eng. sustain. dev. 2009;13(2):128-143. Accessed May 3, 2025. https://jeasd.uomustansiriyah.edu.iq/index.php/jeasd/article/view/1548