Whitehead, N. P., A. Slaouti, and H. Taylor. “OPTIMISATION OF FLOW THROUGH A PNEUMATIC CONTROL VALVE USING CFD ANALYSIS AND EXPERIMENTAL VALIDATION”. International Journal of Fluid Power, vol. 8, no. 3, Nov. 2007, pp. 31-41, https://journals.riverpublishers.com/index.php/IJFP/article/view/536.