“Design of Electrostatic Unipotential Lens Accelerating And Decelerating Operated Under Finite And Infinite Magnification Conditions”. Ibn AL-Haitham Journal For Pure and Applied Sciences, vol. 26, no. 1, Apr. 2017, pp. 167-72, https://jih.uobaghdad.edu.iq/index.php/j/article/view/520.