Falkner, J., A. Ploeckinger, B. Winkler, and R. Scheidl. “FEASIBILITY STUDY OF A NOVEL SLEEVE TYPE SWITCHING VALVE”. International Journal of Fluid Power, vol. 12, no. 2, Aug. 2011, pp. 27-35, https://journals.riverpublishers.com/index.php/IJFP/article/view/467.